blob: e70322b1dd020d27082273df2b394e1d526afabd [file] [log] [blame]
/*
* WUSB Wire Adapter
* Data transfer and URB enqueing
*
* Copyright (C) 2005-2006 Intel Corporation
* Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
*
* How transfers work: get a buffer, break it up in segments (segment
* size is a multiple of the maxpacket size). For each segment issue a
* segment request (struct wa_xfer_*), then send the data buffer if
* out or nothing if in (all over the DTO endpoint).
*
* For each submitted segment request, a notification will come over
* the NEP endpoint and a transfer result (struct xfer_result) will
* arrive in the DTI URB. Read it, get the xfer ID, see if there is
* data coming (inbound transfer), schedule a read and handle it.
*
* Sounds simple, it is a pain to implement.
*
*
* ENTRY POINTS
*
* FIXME
*
* LIFE CYCLE / STATE DIAGRAM
*
* FIXME
*
* THIS CODE IS DISGUSTING
*
* Warned you are; it's my second try and still not happy with it.
*
* NOTES:
*
* - No iso
*
* - Supports DMA xfers, control, bulk and maybe interrupt
*
* - Does not recycle unused rpipes
*
* An rpipe is assigned to an endpoint the first time it is used,
* and then it's there, assigned, until the endpoint is disabled
* (destroyed [{h,d}wahc_op_ep_disable()]. The assignment of the
* rpipe to the endpoint is done under the wa->rpipe_sem semaphore
* (should be a mutex).
*
* Two methods it could be done:
*
* (a) set up a timer every time an rpipe's use count drops to 1
* (which means unused) or when a transfer ends. Reset the
* timer when a xfer is queued. If the timer expires, release
* the rpipe [see rpipe_ep_disable()].
*
* (b) when looking for free rpipes to attach [rpipe_get_by_ep()],
* when none are found go over the list, check their endpoint
* and their activity record (if no last-xfer-done-ts in the
* last x seconds) take it
*
* However, due to the fact that we have a set of limited
* resources (max-segments-at-the-same-time per xfer,
* xfers-per-ripe, blocks-per-rpipe, rpipes-per-host), at the end
* we are going to have to rebuild all this based on an scheduler,
* to where we have a list of transactions to do and based on the
* availability of the different required components (blocks,
* rpipes, segment slots, etc), we go scheduling them. Painful.
*/
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/hash.h>
#include <linux/ratelimit.h>
#include <linux/export.h>
#include <linux/scatterlist.h>
#include "wa-hc.h"
#include "wusbhc.h"
enum {
/* [WUSB] section 8.3.3 allocates 7 bits for the segment index. */
WA_SEGS_MAX = 128,
};
enum wa_seg_status {
WA_SEG_NOTREADY,
WA_SEG_READY,
WA_SEG_DELAYED,
WA_SEG_SUBMITTED,
WA_SEG_PENDING,
WA_SEG_DTI_PENDING,
WA_SEG_DONE,
WA_SEG_ERROR,
WA_SEG_ABORTED,
};
static void wa_xfer_delayed_run(struct wa_rpipe *);
static int __wa_xfer_delayed_run(struct wa_rpipe *rpipe, int *dto_waiting);
/*
* Life cycle governed by 'struct urb' (the refcount of the struct is
* that of the 'struct urb' and usb_free_urb() would free the whole
* struct).
*/
struct wa_seg {
struct urb tr_urb; /* transfer request urb. */
struct urb *isoc_pack_desc_urb; /* for isoc packet descriptor. */
struct urb *dto_urb; /* for data output. */
struct list_head list_node; /* for rpipe->req_list */
struct wa_xfer *xfer; /* out xfer */
u8 index; /* which segment we are */
int isoc_frame_count; /* number of isoc frames in this segment. */
int isoc_frame_offset; /* starting frame offset in the xfer URB. */
/* Isoc frame that the current transfer buffer corresponds to. */
int isoc_frame_index;
int isoc_size; /* size of all isoc frames sent by this seg. */
enum wa_seg_status status;
ssize_t result; /* bytes xfered or error */
struct wa_xfer_hdr xfer_hdr;
};
static inline void wa_seg_init(struct wa_seg *seg)
{
usb_init_urb(&seg->tr_urb);
/* set the remaining memory to 0. */
memset(((void *)seg) + sizeof(seg->tr_urb), 0,
sizeof(*seg) - sizeof(seg->tr_urb));
}
/*
* Protected by xfer->lock
*
*/
struct wa_xfer {
struct kref refcnt;
struct list_head list_node;
spinlock_t lock;
u32 id;
struct wahc *wa; /* Wire adapter we are plugged to */
struct usb_host_endpoint *ep;
struct urb *urb; /* URB we are transferring for */
struct wa_seg **seg; /* transfer segments */
u8 segs, segs_submitted, segs_done;
unsigned is_inbound:1;
unsigned is_dma:1;
size_t seg_size;
int result;
gfp_t gfp; /* allocation mask */
struct wusb_dev *wusb_dev; /* for activity timestamps */
};
static void __wa_populate_dto_urb_isoc(struct wa_xfer *xfer,
struct wa_seg *seg, int curr_iso_frame);
static void wa_complete_remaining_xfer_segs(struct wa_xfer *xfer,
int starting_index, enum wa_seg_status status);
static inline void wa_xfer_init(struct wa_xfer *xfer)
{
kref_init(&xfer->refcnt);
INIT_LIST_HEAD(&xfer->list_node);
spin_lock_init(&xfer->lock);
}
/*
* Destroy a transfer structure
*
* Note that freeing xfer->seg[cnt]->tr_urb will free the containing
* xfer->seg[cnt] memory that was allocated by __wa_xfer_setup_segs.
*/
static void wa_xfer_destroy(struct kref *_xfer)
{
struct wa_xfer *xfer = container_of(_xfer, struct wa_xfer, refcnt);
if (xfer->seg) {
unsigned cnt;
for (cnt = 0; cnt < xfer->segs; cnt++) {
struct wa_seg *seg = xfer->seg[cnt];
if (seg) {
usb_free_urb(seg->isoc_pack_desc_urb);
if (seg->dto_urb) {
kfree(seg->dto_urb->sg);
usb_free_urb(seg->dto_urb);
}
usb_free_urb(&seg->tr_urb);
}
}
kfree(xfer->seg);
}
kfree(xfer);
}
static void wa_xfer_get(struct wa_xfer *xfer)
{
kref_get(&xfer->refcnt);
}
static void wa_xfer_put(struct wa_xfer *xfer)
{
kref_put(&xfer->refcnt, wa_xfer_destroy);
}
/*
* Try to get exclusive access to the DTO endpoint resource. Return true
* if successful.
*/
static inline int __wa_dto_try_get(struct wahc *wa)
{
return (test_and_set_bit(0, &wa->dto_in_use) == 0);
}
/* Release the DTO endpoint resource. */
static inline void __wa_dto_put(struct wahc *wa)
{
clear_bit_unlock(0, &wa->dto_in_use);
}
/* Service RPIPEs that are waiting on the DTO resource. */
static void wa_check_for_delayed_rpipes(struct wahc *wa)
{
unsigned long flags;
int dto_waiting = 0;
struct wa_rpipe *rpipe;
spin_lock_irqsave(&wa->rpipe_lock, flags);
while (!list_empty(&wa->rpipe_delayed_list) && !dto_waiting) {
rpipe = list_first_entry(&wa->rpipe_delayed_list,
struct wa_rpipe, list_node);
__wa_xfer_delayed_run(rpipe, &dto_waiting);
/* remove this RPIPE from the list if it is not waiting. */
if (!dto_waiting) {
pr_debug("%s: RPIPE %d serviced and removed from delayed list.\n",
__func__,
le16_to_cpu(rpipe->descr.wRPipeIndex));
list_del_init(&rpipe->list_node);
}
}
spin_unlock_irqrestore(&wa->rpipe_lock, flags);
}
/* add this RPIPE to the end of the delayed RPIPE list. */
static void wa_add_delayed_rpipe(struct wahc *wa, struct wa_rpipe *rpipe)
{
unsigned long flags;
spin_lock_irqsave(&wa->rpipe_lock, flags);
/* add rpipe to the list if it is not already on it. */
if (list_empty(&rpipe->list_node)) {
pr_debug("%s: adding RPIPE %d to the delayed list.\n",
__func__, le16_to_cpu(rpipe->descr.wRPipeIndex));
list_add_tail(&rpipe->list_node, &wa->rpipe_delayed_list);
}
spin_unlock_irqrestore(&wa->rpipe_lock, flags);
}
/*
* xfer is referenced
*
* xfer->lock has to be unlocked
*
* We take xfer->lock for setting the result; this is a barrier
* against drivers/usb/core/hcd.c:unlink1() being called after we call
* usb_hcd_giveback_urb() and wa_urb_dequeue() trying to get a
* reference to the transfer.
*/
static void wa_xfer_giveback(struct wa_xfer *xfer)
{
unsigned long flags;
spin_lock_irqsave(&xfer->wa->xfer_list_lock, flags);
list_del_init(&xfer->list_node);
usb_hcd_unlink_urb_from_ep(&(xfer->wa->wusb->usb_hcd), xfer->urb);
spin_unlock_irqrestore(&xfer->wa->xfer_list_lock, flags);
/* FIXME: segmentation broken -- kills DWA */
wusbhc_giveback_urb(xfer->wa->wusb, xfer->urb, xfer->result);
wa_put(xfer->wa);
wa_xfer_put(xfer);
}
/*
* xfer is referenced
*
* xfer->lock has to be unlocked
*/
static void wa_xfer_completion(struct wa_xfer *xfer)
{
if (xfer->wusb_dev)
wusb_dev_put(xfer->wusb_dev);
rpipe_put(xfer->ep->hcpriv);
wa_xfer_giveback(xfer);
}
/*
* Initialize a transfer's ID
*
* We need to use a sequential number; if we use the pointer or the
* hash of the pointer, it can repeat over sequential transfers and
* then it will confuse the HWA....wonder why in hell they put a 32
* bit handle in there then.
*/
static void wa_xfer_id_init(struct wa_xfer *xfer)
{
xfer->id = atomic_add_return(1, &xfer->wa->xfer_id_count);
}
/* Return the xfer's ID. */
static inline u32 wa_xfer_id(struct wa_xfer *xfer)
{
return xfer->id;
}
/* Return the xfer's ID in transport format (little endian). */
static inline __le32 wa_xfer_id_le32(struct wa_xfer *xfer)
{
return cpu_to_le32(xfer->id);
}
/*
* If transfer is done, wrap it up and return true
*
* xfer->lock has to be locked
*/
static unsigned __wa_xfer_is_done(struct wa_xfer *xfer)
{
struct device *dev = &xfer->wa->usb_iface->dev;
unsigned result, cnt;
struct wa_seg *seg;
struct urb *urb = xfer->urb;
unsigned found_short = 0;
result = xfer->segs_done == xfer->segs_submitted;
if (result == 0)
goto out;
urb->actual_length = 0;
for (cnt = 0; cnt < xfer->segs; cnt++) {
seg = xfer->seg[cnt];
switch (seg->status) {
case WA_SEG_DONE:
if (found_short && seg->result > 0) {
dev_dbg(dev, "xfer %p ID %08X#%u: bad short segments (%zu)\n",
xfer, wa_xfer_id(xfer), cnt,
seg->result);
urb->status = -EINVAL;
goto out;
}
urb->actual_length += seg->result;
if (!(usb_pipeisoc(xfer->urb->pipe))
&& seg->result < xfer->seg_size
&& cnt != xfer->segs-1)
found_short = 1;
dev_dbg(dev, "xfer %p ID %08X#%u: DONE short %d "
"result %zu urb->actual_length %d\n",
xfer, wa_xfer_id(xfer), seg->index, found_short,
seg->result, urb->actual_length);
break;
case WA_SEG_ERROR:
xfer->result = seg->result;
dev_dbg(dev, "xfer %p ID %08X#%u: ERROR result %zi(0x%08zX)\n",
xfer, wa_xfer_id(xfer), seg->index, seg->result,
seg->result);
goto out;
case WA_SEG_ABORTED:
xfer->result = seg->result;
dev_dbg(dev, "xfer %p ID %08X#%u: ABORTED result %zi(0x%08zX)\n",
xfer, wa_xfer_id(xfer), seg->index, seg->result,
seg->result);
goto out;
default:
dev_warn(dev, "xfer %p ID %08X#%u: is_done bad state %d\n",
xfer, wa_xfer_id(xfer), cnt, seg->status);
xfer->result = -EINVAL;
goto out;
}
}
xfer->result = 0;
out:
return result;
}
/*
* Mark the given segment as done. Return true if this completes the xfer.
* This should only be called for segs that have been submitted to an RPIPE.
* Delayed segs are not marked as submitted so they do not need to be marked
* as done when cleaning up.
*
* xfer->lock has to be locked
*/
static unsigned __wa_xfer_mark_seg_as_done(struct wa_xfer *xfer,
struct wa_seg *seg, enum wa_seg_status status)
{
seg->status = status;
xfer->segs_done++;
/* check for done. */
return __wa_xfer_is_done(xfer);
}
/*
* Search for a transfer list ID on the HCD's URB list
*
* For 32 bit architectures, we use the pointer itself; for 64 bits, a
* 32-bit hash of the pointer.
*
* @returns NULL if not found.
*/
static struct wa_xfer *wa_xfer_get_by_id(struct wahc *wa, u32 id)
{
unsigned long flags;
struct wa_xfer *xfer_itr;
spin_lock_irqsave(&wa->xfer_list_lock, flags);
list_for_each_entry(xfer_itr, &wa->xfer_list, list_node) {
if (id == xfer_itr->id) {
wa_xfer_get(xfer_itr);
goto out;
}
}
xfer_itr = NULL;
out:
spin_unlock_irqrestore(&wa->xfer_list_lock, flags);
return xfer_itr;
}
struct wa_xfer_abort_buffer {
struct urb urb;
struct wahc *wa;
struct wa_xfer_abort cmd;
};
static void __wa_xfer_abort_cb(struct urb *urb)
{
struct wa_xfer_abort_buffer *b = urb->context;
struct wahc *wa = b->wa;
/*
* If the abort request URB failed, then the HWA did not get the abort
* command. Forcibly clean up the xfer without waiting for a Transfer
* Result from the HWA.
*/
if (urb->status < 0) {
struct wa_xfer *xfer;
struct device *dev = &wa->usb_iface->dev;
xfer = wa_xfer_get_by_id(wa, le32_to_cpu(b->cmd.dwTransferID));
dev_err(dev, "%s: Transfer Abort request failed. result: %d\n",
__func__, urb->status);
if (xfer) {
unsigned long flags;
int done, seg_index = 0;
struct wa_rpipe *rpipe = xfer->ep->hcpriv;
dev_err(dev, "%s: cleaning up xfer %p ID 0x%08X.\n",
__func__, xfer, wa_xfer_id(xfer));
spin_lock_irqsave(&xfer->lock, flags);
/* skip done segs. */
while (seg_index < xfer->segs) {
struct wa_seg *seg = xfer->seg[seg_index];
if ((seg->status == WA_SEG_DONE) ||
(seg->status == WA_SEG_ERROR)) {
++seg_index;
} else {
break;
}
}
/* mark remaining segs as aborted. */
wa_complete_remaining_xfer_segs(xfer, seg_index,
WA_SEG_ABORTED);
done = __wa_xfer_is_done(xfer);
spin_unlock_irqrestore(&xfer->lock, flags);
if (done)
wa_xfer_completion(xfer);
wa_xfer_delayed_run(rpipe);
wa_xfer_put(xfer);
} else {
dev_err(dev, "%s: xfer ID 0x%08X already gone.\n",
__func__, le32_to_cpu(b->cmd.dwTransferID));
}
}
wa_put(wa); /* taken in __wa_xfer_abort */
usb_put_urb(&b->urb);
}
/*
* Aborts an ongoing transaction
*
* Assumes the transfer is referenced and locked and in a submitted
* state (mainly that there is an endpoint/rpipe assigned).
*
* The callback (see above) does nothing but freeing up the data by
* putting the URB. Because the URB is allocated at the head of the
* struct, the whole space we allocated is kfreed. *
*/
static int __wa_xfer_abort(struct wa_xfer *xfer)
{
int result = -ENOMEM;
struct device *dev = &xfer->wa->usb_iface->dev;
struct wa_xfer_abort_buffer *b;
struct wa_rpipe *rpipe = xfer->ep->hcpriv;
b = kmalloc(sizeof(*b), GFP_ATOMIC);
if (b == NULL)
goto error_kmalloc;
b->cmd.bLength = sizeof(b->cmd);
b->cmd.bRequestType = WA_XFER_ABORT;
b->cmd.wRPipe = rpipe->descr.wRPipeIndex;
b->cmd.dwTransferID = wa_xfer_id_le32(xfer);
b->wa = wa_get(xfer->wa);
usb_init_urb(&b->urb);
usb_fill_bulk_urb(&b->urb, xfer->wa->usb_dev,
usb_sndbulkpipe(xfer->wa->usb_dev,
xfer->wa->dto_epd->bEndpointAddress),
&b->cmd, sizeof(b->cmd), __wa_xfer_abort_cb, b);
result = usb_submit_urb(&b->urb, GFP_ATOMIC);
if (result < 0)
goto error_submit;
return result; /* callback frees! */
error_submit:
wa_put(xfer->wa);
if (printk_ratelimit())
dev_err(dev, "xfer %p: Can't submit abort request: %d\n",
xfer, result);
kfree(b);
error_kmalloc:
return result;
}
/*
* Calculate the number of isoc frames starting from isoc_frame_offset
* that will fit a in transfer segment.
*/
static int __wa_seg_calculate_isoc_frame_count(struct wa_xfer *xfer,
int isoc_frame_offset, int *total_size)
{
int segment_size = 0, frame_count = 0;
int index = isoc_frame_offset;
struct usb_iso_packet_descriptor *iso_frame_desc =
xfer->urb->iso_frame_desc;
while ((index < xfer->urb->number_of_packets)
&& ((segment_size + iso_frame_desc[index].length)
<= xfer->seg_size)) {
/*
* For Alereon HWA devices, only include an isoc frame in an
* out segment if it is physically contiguous with the previous
* frame. This is required because those devices expect
* the isoc frames to be sent as a single USB transaction as
* opposed to one transaction per frame with standard HWA.
*/
if ((xfer->wa->quirks & WUSB_QUIRK_ALEREON_HWA_CONCAT_ISOC)
&& (xfer->is_inbound == 0)
&& (index > isoc_frame_offset)
&& ((iso_frame_desc[index - 1].offset +
iso_frame_desc[index - 1].length) !=
iso_frame_desc[index].offset))
break;
/* this frame fits. count it. */
++frame_count;
segment_size += iso_frame_desc[index].length;
/* move to the next isoc frame. */
++index;
}
*total_size = segment_size;
return frame_count;
}
/*
*
* @returns < 0 on error, transfer segment request size if ok
*/
static ssize_t __wa_xfer_setup_sizes(struct wa_xfer *xfer,
enum wa_xfer_type *pxfer_type)
{
ssize_t result;
struct device *dev = &xfer->wa->usb_iface->dev;
size_t maxpktsize;
struct urb *urb = xfer->urb;
struct wa_rpipe *rpipe = xfer->ep->hcpriv;
switch (rpipe->descr.bmAttribute & 0x3) {
case USB_ENDPOINT_XFER_CONTROL:
*pxfer_type = WA_XFER_TYPE_CTL;
result = sizeof(struct wa_xfer_ctl);
break;
case USB_ENDPOINT_XFER_INT:
case USB_ENDPOINT_XFER_BULK:
*pxfer_type = WA_XFER_TYPE_BI;
result = sizeof(struct wa_xfer_bi);
break;
case USB_ENDPOINT_XFER_ISOC:
*pxfer_type = WA_XFER_TYPE_ISO;
result = sizeof(struct wa_xfer_hwaiso);
break;
default:
/* never happens */
BUG();
result = -EINVAL; /* shut gcc up */
}
xfer->is_inbound = urb->pipe & USB_DIR_IN ? 1 : 0;
xfer->is_dma = urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP ? 1 : 0;
maxpktsize = le16_to_cpu(rpipe->descr.wMaxPacketSize);
xfer->seg_size = le16_to_cpu(rpipe->descr.wBlocks)
* 1 << (xfer->wa->wa_descr->bRPipeBlockSize - 1);
/* Compute the segment size and make sure it is a multiple of
* the maxpktsize (WUSB1.0[8.3.3.1])...not really too much of
* a check (FIXME) */
if (xfer->seg_size < maxpktsize) {
dev_err(dev,
"HW BUG? seg_size %zu smaller than maxpktsize %zu\n",
xfer->seg_size, maxpktsize);
result = -EINVAL;
goto error;
}
xfer->seg_size = (xfer->seg_size / maxpktsize) * maxpktsize;
if ((rpipe->descr.bmAttribute & 0x3) == USB_ENDPOINT_XFER_ISOC) {
int index = 0;
xfer->segs = 0;
/*
* loop over urb->number_of_packets to determine how many
* xfer segments will be needed to send the isoc frames.
*/
while (index < urb->number_of_packets) {
int seg_size; /* don't care. */
index += __wa_seg_calculate_isoc_frame_count(xfer,
index, &seg_size);
++xfer->segs;
}
} else {
xfer->segs = DIV_ROUND_UP(urb->transfer_buffer_length,
xfer->seg_size);
if (xfer->segs == 0 && *pxfer_type == WA_XFER_TYPE_CTL)
xfer->segs = 1;
}
if (xfer->segs > WA_SEGS_MAX) {
dev_err(dev, "BUG? oops, number of segments %zu bigger than %d\n",
(urb->transfer_buffer_length/xfer->seg_size),
WA_SEGS_MAX);
result = -EINVAL;
goto error;
}
error:
return result;
}
static void __wa_setup_isoc_packet_descr(
struct wa_xfer_packet_info_hwaiso *packet_desc,
struct wa_xfer *xfer,
struct wa_seg *seg) {
struct usb_iso_packet_descriptor *iso_frame_desc =
xfer->urb->iso_frame_desc;
int frame_index;
/* populate isoc packet descriptor. */
packet_desc->bPacketType = WA_XFER_ISO_PACKET_INFO;
packet_desc->wLength = cpu_to_le16(sizeof(*packet_desc) +
(sizeof(packet_desc->PacketLength[0]) *
seg->isoc_frame_count));
for (frame_index = 0; frame_index < seg->isoc_frame_count;
++frame_index) {
int offset_index = frame_index + seg->isoc_frame_offset;
packet_desc->PacketLength[frame_index] =
cpu_to_le16(iso_frame_desc[offset_index].length);
}
}
/* Fill in the common request header and xfer-type specific data. */
static void __wa_xfer_setup_hdr0(struct wa_xfer *xfer,
struct wa_xfer_hdr *xfer_hdr0,
enum wa_xfer_type xfer_type,
size_t xfer_hdr_size)
{
struct wa_rpipe *rpipe = xfer->ep->hcpriv;
struct wa_seg *seg = xfer->seg[0];
xfer_hdr0 = &seg->xfer_hdr;
xfer_hdr0->bLength = xfer_hdr_size;
xfer_hdr0->bRequestType = xfer_type;
xfer_hdr0->wRPipe = rpipe->descr.wRPipeIndex;
xfer_hdr0->dwTransferID = wa_xfer_id_le32(xfer);
xfer_hdr0->bTransferSegment = 0;
switch (xfer_type) {
case WA_XFER_TYPE_CTL: {
struct wa_xfer_ctl *xfer_ctl =
container_of(xfer_hdr0, struct wa_xfer_ctl, hdr);
xfer_ctl->bmAttribute = xfer->is_inbound ? 1 : 0;
memcpy(&xfer_ctl->baSetupData, xfer->urb->setup_packet,
sizeof(xfer_ctl->baSetupData));
break;
}
case WA_XFER_TYPE_BI:
break;
case WA_XFER_TYPE_ISO: {
struct wa_xfer_hwaiso *xfer_iso =
container_of(xfer_hdr0, struct wa_xfer_hwaiso, hdr);
struct wa_xfer_packet_info_hwaiso *packet_desc =
((void *)xfer_iso) + xfer_hdr_size;
/* populate the isoc section of the transfer request. */
xfer_iso->dwNumOfPackets = cpu_to_le32(seg->isoc_frame_count);
/* populate isoc packet descriptor. */
__wa_setup_isoc_packet_descr(packet_desc, xfer, seg);
break;
}
default:
BUG();
};
}
/*
* Callback for the OUT data phase of the segment request
*
* Check wa_seg_tr_cb(); most comments also apply here because this
* function does almost the same thing and they work closely
* together.
*
* If the seg request has failed but this DTO phase has succeeded,
* wa_seg_tr_cb() has already failed the segment and moved the
* status to WA_SEG_ERROR, so this will go through 'case 0' and
* effectively do nothing.
*/
static void wa_seg_dto_cb(struct urb *urb)
{
struct wa_seg *seg = urb->context;
struct wa_xfer *xfer = seg->xfer;
struct wahc *wa;
struct device *dev;
struct wa_rpipe *rpipe;
unsigned long flags;
unsigned rpipe_ready = 0;
int data_send_done = 1, release_dto = 0, holding_dto = 0;
u8 done = 0;
int result;
/* free the sg if it was used. */
kfree(urb->sg);
urb->sg = NULL;
spin_lock_irqsave(&xfer->lock, flags);
wa = xfer->wa;
dev = &wa->usb_iface->dev;
if (usb_pipeisoc(xfer->urb->pipe)) {
/* Alereon HWA sends all isoc frames in a single transfer. */
if (wa->quirks & WUSB_QUIRK_ALEREON_HWA_CONCAT_ISOC)
seg->isoc_frame_index += seg->isoc_frame_count;
else
seg->isoc_frame_index += 1;
if (seg->isoc_frame_index < seg->isoc_frame_count) {
data_send_done = 0;
holding_dto = 1; /* checked in error cases. */
/*
* if this is the last isoc frame of the segment, we
* can release DTO after sending this frame.
*/
if ((seg->isoc_frame_index + 1) >=
seg->isoc_frame_count)
release_dto = 1;
}
dev_dbg(dev, "xfer 0x%08X#%u: isoc frame = %d, holding_dto = %d, release_dto = %d.\n",
wa_xfer_id(xfer), seg->index, seg->isoc_frame_index,
holding_dto, release_dto);
}
spin_unlock_irqrestore(&xfer->lock, flags);
switch (urb->status) {
case 0:
spin_lock_irqsave(&xfer->lock, flags);
seg->result += urb->actual_length;
if (data_send_done) {
dev_dbg(dev, "xfer 0x%08X#%u: data out done (%zu bytes)\n",
wa_xfer_id(xfer), seg->index, seg->result);
if (seg->status < WA_SEG_PENDING)
seg->status = WA_SEG_PENDING;
} else {
/* should only hit this for isoc xfers. */
/*
* Populate the dto URB with the next isoc frame buffer,
* send the URB and release DTO if we no longer need it.
*/
__wa_populate_dto_urb_isoc(xfer, seg,
seg->isoc_frame_offset + seg->isoc_frame_index);
/* resubmit the URB with the next isoc frame. */
/* take a ref on resubmit. */
wa_xfer_get(xfer);
result = usb_submit_urb(seg->dto_urb, GFP_ATOMIC);
if (result < 0) {
dev_err(dev, "xfer 0x%08X#%u: DTO submit failed: %d\n",
wa_xfer_id(xfer), seg->index, result);
spin_unlock_irqrestore(&xfer->lock, flags);
goto error_dto_submit;
}
}
spin_unlock_irqrestore(&xfer->lock, flags);
if (release_dto) {
__wa_dto_put(wa);
wa_check_for_delayed_rpipes(wa);
}
break;
case -ECONNRESET: /* URB unlinked; no need to do anything */
case -ENOENT: /* as it was done by the who unlinked us */
if (holding_dto) {
__wa_dto_put(wa);
wa_check_for_delayed_rpipes(wa);
}
break;
default: /* Other errors ... */
dev_err(dev, "xfer 0x%08X#%u: data out error %d\n",
wa_xfer_id(xfer), seg->index, urb->status);
goto error_default;
}
/* taken when this URB was submitted. */
wa_xfer_put(xfer);
return;
error_dto_submit:
/* taken on resubmit attempt. */
wa_xfer_put(xfer);
error_default:
spin_lock_irqsave(&xfer->lock, flags);
rpipe = xfer->ep->hcpriv;
if (edc_inc(&wa->nep_edc, EDC_MAX_ERRORS,
EDC_ERROR_TIMEFRAME)){
dev_err(dev, "DTO: URB max acceptable errors exceeded, resetting device\n");
wa_reset_all(wa);
}
if (seg->status != WA_SEG_ERROR) {
seg->result = urb->status;
__wa_xfer_abort(xfer);
rpipe_ready = rpipe_avail_inc(rpipe);
done = __wa_xfer_mark_seg_as_done(xfer, seg, WA_SEG_ERROR);
}
spin_unlock_irqrestore(&xfer->lock, flags);
if (holding_dto) {
__wa_dto_put(wa);
wa_check_for_delayed_rpipes(wa);
}
if (done)
wa_xfer_completion(xfer);
if (rpipe_ready)
wa_xfer_delayed_run(rpipe);
/* taken when this URB was submitted. */
wa_xfer_put(xfer);
}
/*
* Callback for the isoc packet descriptor phase of the segment request
*
* Check wa_seg_tr_cb(); most comments also apply here because this
* function does almost the same thing and they work closely
* together.
*
* If the seg request has failed but this phase has succeeded,
* wa_seg_tr_cb() has already failed the segment and moved the
* status to WA_SEG_ERROR, so this will go through 'case 0' and
* effectively do nothing.
*/
static void wa_seg_iso_pack_desc_cb(struct urb *urb)
{
struct wa_seg *seg = urb->context;
struct wa_xfer *xfer = seg->xfer;
struct wahc *wa;
struct device *dev;
struct wa_rpipe *rpipe;
unsigned long flags;
unsigned rpipe_ready = 0;
u8 done = 0;
switch (urb->status) {
case 0:
spin_lock_irqsave(&xfer->lock, flags);
wa = xfer->wa;
dev = &wa->usb_iface->dev;
dev_dbg(dev, "iso xfer %08X#%u: packet descriptor done\n",
wa_xfer_id(xfer), seg->index);
if (xfer->is_inbound && seg->status < WA_SEG_PENDING)
seg->status = WA_SEG_PENDING;
spin_unlock_irqrestore(&xfer->lock, flags);
break;
case -ECONNRESET: /* URB unlinked; no need to do anything */
case -ENOENT: /* as it was done by the who unlinked us */
break;
default: /* Other errors ... */
spin_lock_irqsave(&xfer->lock, flags);
wa = xfer->wa;
dev = &wa->usb_iface->dev;
rpipe = xfer->ep->hcpriv;
pr_err_ratelimited("iso xfer %08X#%u: packet descriptor error %d\n",
wa_xfer_id(xfer), seg->index, urb->status);
if (edc_inc(&wa->nep_edc, EDC_MAX_ERRORS,
EDC_ERROR_TIMEFRAME)){
dev_err(dev, "iso xfer: URB max acceptable errors exceeded, resetting device\n");
wa_reset_all(wa);
}
if (seg->status != WA_SEG_ERROR) {
usb_unlink_urb(seg->dto_urb);
seg->result = urb->status;
__wa_xfer_abort(xfer);
rpipe_ready = rpipe_avail_inc(rpipe);
done = __wa_xfer_mark_seg_as_done(xfer, seg,
WA_SEG_ERROR);
}
spin_unlock_irqrestore(&xfer->lock, flags);
if (done)
wa_xfer_completion(xfer);
if (rpipe_ready)
wa_xfer_delayed_run(rpipe);
}
/* taken when this URB was submitted. */
wa_xfer_put(xfer);
}
/*
* Callback for the segment request
*
* If successful transition state (unless already transitioned or
* outbound transfer); otherwise, take a note of the error, mark this
* segment done and try completion.
*
* Note we don't access until we are sure that the transfer hasn't
* been cancelled (ECONNRESET, ENOENT), which could mean that
* seg->xfer could be already gone.
*
* We have to check before setting the status to WA_SEG_PENDING
* because sometimes the xfer result callback arrives before this
* callback (geeeeeeze), so it might happen that we are already in
* another state. As well, we don't set it if the transfer is not inbound,
* as in that case, wa_seg_dto_cb will do it when the OUT data phase
* finishes.
*/
static void wa_seg_tr_cb(struct urb *urb)
{
struct wa_seg *seg = urb->context;
struct wa_xfer *xfer = seg->xfer;
struct wahc *wa;
struct device *dev;
struct wa_rpipe *rpipe;
unsigned long flags;
unsigned rpipe_ready;
u8 done = 0;
switch (urb->status) {
case 0:
spin_lock_irqsave(&xfer->lock, flags);
wa = xfer->wa;
dev = &wa->usb_iface->dev;
dev_dbg(dev, "xfer %p ID 0x%08X#%u: request done\n",
xfer, wa_xfer_id(xfer), seg->index);
if (xfer->is_inbound &&
seg->status < WA_SEG_PENDING &&
!(usb_pipeisoc(xfer->urb->pipe)))
seg->status = WA_SEG_PENDING;
spin_unlock_irqrestore(&xfer->lock, flags);
break;
case -ECONNRESET: /* URB unlinked; no need to do anything */
case -ENOENT: /* as it was done by the who unlinked us */
break;
default: /* Other errors ... */
spin_lock_irqsave(&xfer->lock, flags);
wa = xfer->wa;
dev = &wa->usb_iface->dev;
rpipe = xfer->ep->hcpriv;
if (printk_ratelimit())
dev_err(dev, "xfer %p ID 0x%08X#%u: request error %d\n",
xfer, wa_xfer_id(xfer), seg->index,
urb->status);
if (edc_inc(&wa->nep_edc, EDC_MAX_ERRORS,
EDC_ERROR_TIMEFRAME)){
dev_err(dev, "DTO: URB max acceptable errors "
"exceeded, resetting device\n");
wa_reset_all(wa);
}
usb_unlink_urb(seg->isoc_pack_desc_urb);
usb_unlink_urb(seg->dto_urb);
seg->result = urb->status;
__wa_xfer_abort(xfer);
rpipe_ready = rpipe_avail_inc(rpipe);
done = __wa_xfer_mark_seg_as_done(xfer, seg, WA_SEG_ERROR);
spin_unlock_irqrestore(&xfer->lock, flags);
if (done)
wa_xfer_completion(xfer);
if (rpipe_ready)
wa_xfer_delayed_run(rpipe);
}
/* taken when this URB was submitted. */
wa_xfer_put(xfer);
}
/*
* Allocate an SG list to store bytes_to_transfer bytes and copy the
* subset of the in_sg that matches the buffer subset
* we are about to transfer.
*/
static struct scatterlist *wa_xfer_create_subset_sg(struct scatterlist *in_sg,
const unsigned int bytes_transferred,
const unsigned int bytes_to_transfer, int *out_num_sgs)
{
struct scatterlist *out_sg;
unsigned int bytes_processed = 0, offset_into_current_page_data = 0,
nents;
struct scatterlist *current_xfer_sg = in_sg;
struct scatterlist *current_seg_sg, *last_seg_sg;
/* skip previously transferred pages. */
while ((current_xfer_sg) &&
(bytes_processed < bytes_transferred)) {
bytes_processed += current_xfer_sg->length;
/* advance the sg if current segment starts on or past the
next page. */
if (bytes_processed <= bytes_transferred)
current_xfer_sg = sg_next(current_xfer_sg);
}
/* the data for the current segment starts in current_xfer_sg.
calculate the offset. */
if (bytes_processed > bytes_transferred) {
offset_into_current_page_data = current_xfer_sg->length -
(bytes_processed - bytes_transferred);
}
/* calculate the number of pages needed by this segment. */
nents = DIV_ROUND_UP((bytes_to_transfer +
offset_into_current_page_data +
current_xfer_sg->offset),
PAGE_SIZE);
out_sg = kmalloc((sizeof(struct scatterlist) * nents), GFP_ATOMIC);
if (out_sg) {
sg_init_table(out_sg, nents);
/* copy the portion of the incoming SG that correlates to the
* data to be transferred by this segment to the segment SG. */
last_seg_sg = current_seg_sg = out_sg;
bytes_processed = 0;
/* reset nents and calculate the actual number of sg entries
needed. */
nents = 0;
while ((bytes_processed < bytes_to_transfer) &&
current_seg_sg && current_xfer_sg) {
unsigned int page_len = min((current_xfer_sg->length -
offset_into_current_page_data),
(bytes_to_transfer - bytes_processed));
sg_set_page(current_seg_sg, sg_page(current_xfer_sg),
page_len,
current_xfer_sg->offset +
offset_into_current_page_data);
bytes_processed += page_len;
last_seg_sg = current_seg_sg;
current_seg_sg = sg_next(current_seg_sg);
current_xfer_sg = sg_next(current_xfer_sg);
/* only the first page may require additional offset. */
offset_into_current_page_data = 0;
nents++;
}
/* update num_sgs and terminate the list since we may have
* concatenated pages. */
sg_mark_end(last_seg_sg);
*out_num_sgs = nents;
}
return out_sg;
}
/*
* Populate DMA buffer info for the isoc dto urb.
*/
static void __wa_populate_dto_urb_isoc(struct wa_xfer *xfer,
struct wa_seg *seg, int curr_iso_frame)
{
seg->dto_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
seg->dto_urb->sg = NULL;
seg->dto_urb->num_sgs = 0;
/* dto urb buffer address pulled from iso_frame_desc. */
seg->dto_urb->transfer_dma = xfer->urb->transfer_dma +
xfer->urb->iso_frame_desc[curr_iso_frame].offset;
/* The Alereon HWA sends a single URB with all isoc segs. */
if (xfer->wa->quirks & WUSB_QUIRK_ALEREON_HWA_CONCAT_ISOC)
seg->dto_urb->transfer_buffer_length = seg->isoc_size;
else
seg->dto_urb->transfer_buffer_length =
xfer->urb->iso_frame_desc[curr_iso_frame].length;
}
/*
* Populate buffer ptr and size, DMA buffer or SG list for the dto urb.
*/
static int __wa_populate_dto_urb(struct wa_xfer *xfer,
struct wa_seg *seg, size_t buf_itr_offset, size_t buf_itr_size)
{
int result = 0;
if (xfer->is_dma) {
seg->dto_urb->transfer_dma =
xfer->urb->transfer_dma + buf_itr_offset;
seg->dto_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
seg->dto_urb->sg = NULL;
seg->dto_urb->num_sgs = 0;
} else {
/* do buffer or SG processing. */
seg->dto_urb->transfer_flags &=
~URB_NO_TRANSFER_DMA_MAP;
/* this should always be 0 before a resubmit. */
seg->dto_urb->num_mapped_sgs = 0;
if (xfer->urb->transfer_buffer) {
seg->dto_urb->transfer_buffer =
xfer->urb->transfer_buffer +
buf_itr_offset;
seg->dto_urb->sg = NULL;
seg->dto_urb->num_sgs = 0;
} else {
seg->dto_urb->transfer_buffer = NULL;
/*
* allocate an SG list to store seg_size bytes
* and copy the subset of the xfer->urb->sg that
* matches the buffer subset we are about to
* read.
*/
seg->dto_urb->sg = wa_xfer_create_subset_sg(
xfer->urb->sg,
buf_itr_offset, buf_itr_size,
&(seg->dto_urb->num_sgs));
if (!(seg->dto_urb->sg))
result = -ENOMEM;
}
}
seg->dto_urb->transfer_buffer_length = buf_itr_size;
return result;
}
/*
* Allocate the segs array and initialize each of them
*
* The segments are freed by wa_xfer_destroy() when the xfer use count
* drops to zero; however, because each segment is given the same life
* cycle as the USB URB it contains, it is actually freed by
* usb_put_urb() on the contained USB URB (twisted, eh?).
*/
static int __wa_xfer_setup_segs(struct wa_xfer *xfer, size_t xfer_hdr_size)
{
int result, cnt, isoc_frame_offset = 0;
size_t alloc_size = sizeof(*xfer->seg[0])
- sizeof(xfer->seg[0]->xfer_hdr) + xfer_hdr_size;
struct usb_device *usb_dev = xfer->wa->usb_dev;
const struct usb_endpoint_descriptor *dto_epd = xfer->wa->dto_epd;
struct wa_seg *seg;
size_t buf_itr, buf_size, buf_itr_size;
result = -ENOMEM;
xfer->seg = kcalloc(xfer->segs, sizeof(xfer->seg[0]), GFP_ATOMIC);
if (xfer->seg == NULL)
goto error_segs_kzalloc;
buf_itr = 0;
buf_size = xfer->urb->transfer_buffer_length;
for (cnt = 0; cnt < xfer->segs; cnt++) {
size_t iso_pkt_descr_size = 0;
int seg_isoc_frame_count = 0, seg_isoc_size = 0;
/*
* Adjust the size of the segment object to contain space for
* the isoc packet descriptor buffer.
*/
if (usb_pipeisoc(xfer->urb->pipe)) {
seg_isoc_frame_count =
__wa_seg_calculate_isoc_frame_count(xfer,
isoc_frame_offset, &seg_isoc_size);
iso_pkt_descr_size =
sizeof(struct wa_xfer_packet_info_hwaiso) +
(seg_isoc_frame_count * sizeof(__le16));
}
result = -ENOMEM;
seg = xfer->seg[cnt] = kmalloc(alloc_size + iso_pkt_descr_size,
GFP_ATOMIC);
if (seg == NULL)
goto error_seg_kmalloc;
wa_seg_init(seg);
seg->xfer = xfer;
seg->index = cnt;
usb_fill_bulk_urb(&seg->tr_urb, usb_dev,
usb_sndbulkpipe(usb_dev,
dto_epd->bEndpointAddress),
&seg->xfer_hdr, xfer_hdr_size,
wa_seg_tr_cb, seg);
buf_itr_size = min(buf_size, xfer->seg_size);
if (usb_pipeisoc(xfer->urb->pipe)) {
seg->isoc_frame_count = seg_isoc_frame_count;
seg->isoc_frame_offset = isoc_frame_offset;
seg->isoc_size = seg_isoc_size;
/* iso packet descriptor. */
seg->isoc_pack_desc_urb =
usb_alloc_urb(0, GFP_ATOMIC);
if (seg->isoc_pack_desc_urb == NULL)
goto error_iso_pack_desc_alloc;
/*
* The buffer for the isoc packet descriptor starts
* after the transfer request header in the
* segment object memory buffer.
*/
usb_fill_bulk_urb(
seg->isoc_pack_desc_urb, usb_dev,
usb_sndbulkpipe(usb_dev,
dto_epd->bEndpointAddress),
(void *)(&seg->xfer_hdr) +
xfer_hdr_size,
iso_pkt_descr_size,
wa_seg_iso_pack_desc_cb, seg);
/* adjust starting frame offset for next seg. */
isoc_frame_offset += seg_isoc_frame_count;
}
if (xfer->is_inbound == 0 && buf_size > 0) {
/* outbound data. */
seg->dto_urb = usb_alloc_urb(0, GFP_ATOMIC);
if (seg->dto_urb == NULL)
goto error_dto_alloc;
usb_fill_bulk_urb(
seg->dto_urb, usb_dev,
usb_sndbulkpipe(usb_dev,
dto_epd->bEndpointAddress),
NULL, 0, wa_seg_dto_cb, seg);
if (usb_pipeisoc(xfer->urb->pipe)) {
/*
* Fill in the xfer buffer information for the
* first isoc frame. Subsequent frames in this
* segment will be filled in and sent from the
* DTO completion routine, if needed.
*/
__wa_populate_dto_urb_isoc(xfer, seg,
seg->isoc_frame_offset);
} else {
/* fill in the xfer buffer information. */
result = __wa_populate_dto_urb(xfer, seg,
buf_itr, buf_itr_size);
if (result < 0)
goto error_seg_outbound_populate;
buf_itr += buf_itr_size;
buf_size -= buf_itr_size;
}
}
seg->status = WA_SEG_READY;
}
return 0;
/*
* Free the memory for the current segment which failed to init.
* Use the fact that cnt is left at were it failed. The remaining
* segments will be cleaned up by wa_xfer_destroy.
*/
error_seg_outbound_populate:
usb_free_urb(xfer->seg[cnt]->dto_urb);
error_dto_alloc:
usb_free_urb(xfer->seg[cnt]->isoc_pack_desc_urb);
error_iso_pack_desc_alloc:
kfree(xfer->seg[cnt]);
xfer->seg[cnt] = NULL;
error_seg_kmalloc:
error_segs_kzalloc:
return result;
}
/*
* Allocates all the stuff needed to submit a transfer
*
* Breaks the whole data buffer in a list of segments, each one has a
* structure allocated to it and linked in xfer->seg[index]
*
* FIXME: merge setup_segs() and the last part of this function, no
* need to do two for loops when we could run everything in a
* single one
*/
static int __wa_xfer_setup(struct wa_xfer *xfer, struct urb *urb)
{
int result;
struct device *dev = &xfer->wa->usb_iface->dev;
enum wa_xfer_type xfer_type = 0; /* shut up GCC */
size_t xfer_hdr_size, cnt, transfer_size;
struct wa_xfer_hdr *xfer_hdr0, *xfer_hdr;
result = __wa_xfer_setup_sizes(xfer, &xfer_type);
if (result < 0)
goto error_setup_sizes;
xfer_hdr_size = result;
result = __wa_xfer_setup_segs(xfer, xfer_hdr_size);
if (result < 0) {
dev_err(dev, "xfer %p: Failed to allocate %d segments: %d\n",
xfer, xfer->segs, result);
goto error_setup_segs;
}
/* Fill the first header */
xfer_hdr0 = &xfer->seg[0]->xfer_hdr;
wa_xfer_id_init(xfer);
__wa_xfer_setup_hdr0(xfer, xfer_hdr0, xfer_type, xfer_hdr_size);
/* Fill remaining headers */
xfer_hdr = xfer_hdr0;
if (xfer_type == WA_XFER_TYPE_ISO) {
xfer_hdr0->dwTransferLength =
cpu_to_le32(xfer->seg[0]->isoc_size);
for (cnt = 1; cnt < xfer->segs; cnt++) {
struct wa_xfer_packet_info_hwaiso *packet_desc;
struct wa_seg *seg = xfer->seg[cnt];
struct wa_xfer_hwaiso *xfer_iso;
xfer_hdr = &seg->xfer_hdr;
xfer_iso = container_of(xfer_hdr,
struct wa_xfer_hwaiso, hdr);
packet_desc = ((void *)xfer_hdr) + xfer_hdr_size;
/*
* Copy values from the 0th header. Segment specific
* values are set below.
*/
memcpy(xfer_hdr, xfer_hdr0, xfer_hdr_size);
xfer_hdr->bTransferSegment = cnt;
xfer_hdr->dwTransferLength =
cpu_to_le32(seg->isoc_size);
xfer_iso->dwNumOfPackets =
cpu_to_le32(seg->isoc_frame_count);
__wa_setup_isoc_packet_descr(packet_desc, xfer, seg);
seg->status = WA_SEG_READY;
}
} else {
transfer_size = urb->transfer_buffer_length;
xfer_hdr0->dwTransferLength = transfer_size > xfer->seg_size ?
cpu_to_le32(xfer->seg_size) :
cpu_to_le32(transfer_size);
transfer_size -= xfer->seg_size;
for (cnt = 1; cnt < xfer->segs; cnt++) {
xfer_hdr = &xfer->seg[cnt]->xfer_hdr;
memcpy(xfer_hdr, xfer_hdr0, xfer_hdr_size);
xfer_hdr->bTransferSegment = cnt;
xfer_hdr->dwTransferLength =
transfer_size > xfer->seg_size ?
cpu_to_le32(xfer->seg_size)
: cpu_to_le32(transfer_size);
xfer->seg[cnt]->status = WA_SEG_READY;
transfer_size -= xfer->seg_size;
}
}
xfer_hdr->bTransferSegment |= 0x80; /* this is the last segment */
result = 0;
error_setup_segs:
error_setup_sizes:
return result;
}
/*
*
*
* rpipe->seg_lock is held!
*/
static int __wa_seg_submit(struct wa_rpipe *rpipe, struct wa_xfer *xfer,
struct wa_seg *seg, int *dto_done)
{
int result;
/* default to done unless we encounter a multi-frame isoc segment. */
*dto_done = 1;
/*
* Take a ref for each segment urb so the xfer cannot disappear until
* all of the callbacks run.
*/
wa_xfer_get(xfer);
/* submit the transfer request. */
seg->status = WA_SEG_SUBMITTED;
result = usb_submit_urb(&seg->tr_urb, GFP_ATOMIC);
if (result < 0) {
pr_err("%s: xfer %p#%u: REQ submit failed: %d\n",
__func__, xfer, seg->index, result);
wa_xfer_put(xfer);
goto error_tr_submit;
}
/* submit the isoc packet descriptor if present. */
if (seg->isoc_pack_desc_urb) {
wa_xfer_get(xfer);
result = usb_submit_urb(seg->isoc_pack_desc_urb, GFP_ATOMIC);
seg->isoc_frame_index = 0;
if (result < 0) {
pr_err("%s: xfer %p#%u: ISO packet descriptor submit failed: %d\n",
__func__, xfer, seg->index, result);
wa_xfer_put(xfer);
goto error_iso_pack_desc_submit;
}
}
/* submit the out data if this is an out request. */
if (seg->dto_urb) {
struct wahc *wa = xfer->wa;
wa_xfer_get(xfer);
result = usb_submit_urb(seg->dto_urb, GFP_ATOMIC);
if (result < 0) {
pr_err("%s: xfer %p#%u: DTO submit failed: %d\n",
__func__, xfer, seg->index, result);
wa_xfer_put(xfer);
goto error_dto_submit;
}
/*
* If this segment contains more than one isoc frame, hold
* onto the dto resource until we send all frames.
* Only applies to non-Alereon devices.
*/
if (((wa->quirks & WUSB_QUIRK_ALEREON_HWA_CONCAT_ISOC) == 0)
&& (seg->isoc_frame_count > 1))
*dto_done = 0;
}
rpipe_avail_dec(rpipe);
return 0;
error_dto_submit:
usb_unlink_urb(seg->isoc_pack_desc_urb);
error_iso_pack_desc_submit:
usb_unlink_urb(&seg->tr_urb);
error_tr_submit:
seg->status = WA_SEG_ERROR;
seg->result = result;
*dto_done = 1;
return result;
}
/*
* Execute more queued request segments until the maximum concurrent allowed.
* Return true if the DTO resource was acquired and released.
*
* The ugly unlock/lock sequence on the error path is needed as the
* xfer->lock normally nests the seg_lock and not viceversa.
*/
static int __wa_xfer_delayed_run(struct wa_rpipe *rpipe, int *dto_waiting)
{
int result, dto_acquired = 0, dto_done = 0;
struct device *dev = &rpipe->wa->usb_iface->dev;
struct wa_seg *seg;
struct wa_xfer *xfer;
unsigned long flags;
*dto_waiting = 0;
spin_lock_irqsave(&rpipe->seg_lock, flags);
while (atomic_read(&rpipe->segs_available) > 0
&& !list_empty(&rpipe->seg_list)
&& (dto_acquired = __wa_dto_try_get(rpipe->wa))) {
seg = list_first_entry(&(rpipe->seg_list), struct wa_seg,
list_node);
list_del(&seg->list_node);
xfer = seg->xfer;
/*
* Get a reference to the xfer in case the callbacks for the
* URBs submitted by __wa_seg_submit attempt to complete
* the xfer before this function completes.
*/
wa_xfer_get(xfer);
result = __wa_seg_submit(rpipe, xfer, seg, &dto_done);
/* release the dto resource if this RPIPE is done with it. */
if (dto_done)
__wa_dto_put(rpipe->wa);
dev_dbg(dev, "xfer %p ID %08X#%u submitted from delayed [%d segments available] %d\n",
xfer, wa_xfer_id(xfer), seg->index,
atomic_read(&rpipe->segs_available), result);
if (unlikely(result < 0)) {
int done;
spin_unlock_irqrestore(&rpipe->seg_lock, flags);
spin_lock_irqsave(&xfer->lock, flags);
__wa_xfer_abort(xfer);
/*
* This seg was marked as submitted when it was put on
* the RPIPE seg_list. Mark it done.
*/
xfer->segs_done++;
done = __wa_xfer_is_done(xfer);
spin_unlock_irqrestore(&xfer->lock, flags);
if (done)
wa_xfer_completion(xfer);
spin_lock_irqsave(&rpipe->seg_lock, flags);
}
wa_xfer_put(xfer);
}
/*
* Mark this RPIPE as waiting if dto was not acquired, there are
* delayed segs and no active transfers to wake us up later.
*/
if (!dto_acquired && !list_empty(&rpipe->seg_list)
&& (atomic_read(&rpipe->segs_available) ==
le16_to_cpu(rpipe->descr.wRequests)))
*dto_waiting = 1;
spin_unlock_irqrestore(&rpipe->seg_lock, flags);
return dto_done;
}
static void wa_xfer_delayed_run(struct wa_rpipe *rpipe)
{
int dto_waiting;
int dto_done = __wa_xfer_delayed_run(rpipe, &dto_waiting);
/*
* If this RPIPE is waiting on the DTO resource, add it to the tail of
* the waiting list.
* Otherwise, if the WA DTO resource was acquired and released by
* __wa_xfer_delayed_run, another RPIPE may have attempted to acquire
* DTO and failed during that time. Check the delayed list and process
* any waiters. Start searching from the next RPIPE index.
*/
if (dto_waiting)
wa_add_delayed_rpipe(rpipe->wa, rpipe);
else if (dto_done)
wa_check_for_delayed_rpipes(rpipe->wa);
}
/*
*
* xfer->lock is taken
*
* On failure submitting we just stop submitting and return error;
* wa_urb_enqueue_b() will execute the completion path
*/
static int __wa_xfer_submit(struct wa_xfer *xfer)
{
int result, dto_acquired = 0, dto_done = 0, dto_waiting = 0;
struct wahc *wa = xfer->wa;
struct device *dev = &wa->usb_iface->dev;
unsigned cnt;
struct wa_seg *seg;
unsigned long flags;
struct wa_rpipe *rpipe = xfer->ep->hcpriv;
size_t maxrequests = le16_to_cpu(rpipe->descr.wRequests);
u8 available;
u8 empty;
spin_lock_irqsave(&wa->xfer_list_lock, flags);
list_add_tail(&xfer->list_node, &wa->xfer_list);
spin_unlock_irqrestore(&wa->xfer_list_lock, flags);
BUG_ON(atomic_read(&rpipe->segs_available) > maxrequests);
result = 0;
spin_lock_irqsave(&rpipe->seg_lock, flags);
for (cnt = 0; cnt < xfer->segs; cnt++) {
int delay_seg = 1;
available = atomic_read(&rpipe->segs_available);
empty = list_empty(&rpipe->seg_list);
seg = xfer->seg[cnt];
if (available && empty) {
/*
* Only attempt to acquire DTO if we have a segment
* to send.
*/
dto_acquired = __wa_dto_try_get(rpipe->wa);
if (dto_acquired) {
delay_seg = 0;
result = __wa_seg_submit(rpipe, xfer, seg,
&dto_done);
dev_dbg(dev, "xfer %p ID 0x%08X#%u: available %u empty %u submitted\n",
xfer, wa_xfer_id(xfer), cnt, available,
empty);
if (dto_done)
__wa_dto_put(rpipe->wa);
if (result < 0) {
__wa_xfer_abort(xfer);
goto error_seg_submit;
}
}
}
if (delay_seg) {
dev_dbg(dev, "xfer %p ID 0x%08X#%u: available %u empty %u delayed\n",
xfer, wa_xfer_id(xfer), cnt, available, empty);
seg->status = WA_SEG_DELAYED;
list_add_tail(&seg->list_node, &rpipe->seg_list);
}
xfer->segs_submitted++;
}
error_seg_submit:
/*
* Mark this RPIPE as waiting if dto was not acquired, there are
* delayed segs and no active transfers to wake us up later.
*/
if (!dto_acquired && !list_empty(&rpipe->seg_list)
&& (atomic_read(&rpipe->segs_available) ==
le16_to_cpu(rpipe->descr.wRequests)))
dto_waiting = 1;
spin_unlock_irqrestore(&rpipe->seg_lock, flags);
if (dto_waiting)
wa_add_delayed_rpipe(rpipe->wa, rpipe);
else if (dto_done)
wa_check_for_delayed_rpipes(rpipe->wa);
return result;
}
/*
* Second part of a URB/transfer enqueuement
*
* Assumes this comes from wa_urb_enqueue() [maybe through
* wa_urb_enqueue_run()]. At this point:
*
* xfer->wa filled and refcounted
* xfer->ep filled with rpipe refcounted if
* delayed == 0
* xfer->urb filled and refcounted (this is the case when called
* from wa_urb_enqueue() as we come from usb_submit_urb()
* and when called by wa_urb_enqueue_run(), as we took an
* extra ref dropped by _run() after we return).
* xfer->gfp filled
*
* If we fail at __wa_xfer_submit(), then we just check if we are done
* and if so, we run the completion procedure. However, if we are not
* yet done, we do nothing and wait for the completion handlers from
* the submitted URBs or from the xfer-result path to kick in. If xfer
* result never kicks in, the xfer will timeout from the USB code and
* dequeue() will be called.
*/
static int wa_urb_enqueue_b(struct wa_xfer *xfer)
{
int result;
unsigned long flags;
struct urb *urb = xfer->urb;
struct wahc *wa = xfer->wa;
struct wusbhc *wusbhc = wa->wusb;
struct wusb_dev *wusb_dev;
unsigned done;
result = rpipe_get_by_ep(wa, xfer->ep, urb, xfer->gfp);
if (result < 0) {
pr_err("%s: error_rpipe_get\n", __func__);
goto error_rpipe_get;
}
result = -ENODEV;
/* FIXME: segmentation broken -- kills DWA */
mutex_lock(&wusbhc->mutex); /* get a WUSB dev */
if (urb->dev == NULL) {
mutex_unlock(&wusbhc->mutex);
pr_err("%s: error usb dev gone\n", __func__);
goto error_dev_gone;
}
wusb_dev = __wusb_dev_get_by_usb_dev(wusbhc, urb->dev);
if (wusb_dev == NULL) {
mutex_unlock(&wusbhc->mutex);
dev_err(&(urb->dev->dev), "%s: error wusb dev gone\n",
__func__);
goto error_dev_gone;
}
mutex_unlock(&wusbhc->mutex);
spin_lock_irqsave(&xfer->lock, flags);
xfer->wusb_dev = wusb_dev;
result = urb->status;
if (urb->status != -EINPROGRESS) {
dev_err(&(urb->dev->dev), "%s: error_dequeued\n", __func__);
goto error_dequeued;
}
result = __wa_xfer_setup(xfer, urb);
if (result < 0) {
dev_err(&(urb->dev->dev), "%s: error_xfer_setup\n", __func__);
goto error_xfer_setup;
}
/*
* Get a xfer reference since __wa_xfer_submit starts asynchronous
* operations that may try to complete the xfer before this function
* exits.
*/
wa_xfer_get(xfer);
result = __wa_xfer_submit(xfer);
if (result < 0) {
dev_err(&(urb->dev->dev), "%s: error_xfer_submit\n", __func__);
goto error_xfer_submit;
}
spin_unlock_irqrestore(&xfer->lock, flags);
wa_xfer_put(xfer);
return 0;
/*
* this is basically wa_xfer_completion() broken up wa_xfer_giveback()
* does a wa_xfer_put() that will call wa_xfer_destroy() and undo
* setup().
*/
error_xfer_setup:
error_dequeued:
spin_unlock_irqrestore(&xfer->lock, flags);
/* FIXME: segmentation broken, kills DWA */
if (wusb_dev)
wusb_dev_put(wusb_dev);
error_dev_gone:
rpipe_put(xfer->ep->hcpriv);
error_rpipe_get:
xfer->result = result;
return result;
error_xfer_submit:
done = __wa_xfer_is_done(xfer);
xfer->result = result;
spin_unlock_irqrestore(&xfer->lock, flags);
if (done)
wa_xfer_completion(xfer);
wa_xfer_put(xfer);
/* return success since the completion routine will run. */
return 0;
}
/*
* Execute the delayed transfers in the Wire Adapter @wa
*
* We need to be careful here, as dequeue() could be called in the
* middle. That's why we do the whole thing under the
* wa->xfer_list_lock. If dequeue() jumps in, it first locks xfer->lock
* and then checks the list -- so as we would be acquiring in inverse
* order, we move the delayed list to a separate list while locked and then
* submit them without the list lock held.
*/
void wa_urb_enqueue_run(struct work_struct *ws)
{
struct wahc *wa = container_of(ws, struct wahc, xfer_enqueue_work);
struct wa_xfer *xfer, *next;
struct urb *urb;
LIST_HEAD(tmp_list);
/* Create a copy of the wa->xfer_delayed_list while holding the lock */
spin_lock_irq(&wa->xfer_list_lock);
list_cut_position(&tmp_list, &wa->xfer_delayed_list,
wa->xfer_delayed_list.prev);
spin_unlock_irq(&wa->xfer_list_lock);
/*
* enqueue from temp list without list lock held since wa_urb_enqueue_b
* can take xfer->lock as well as lock mutexes.
*/
list_for_each_entry_safe(xfer, next, &tmp_list, list_node) {
list_del_init(&xfer->list_node);
urb = xfer->urb;
if (wa_urb_enqueue_b(xfer) < 0)
wa_xfer_giveback(xfer);
usb_put_urb(urb); /* taken when queuing */
}
}
EXPORT_SYMBOL_GPL(wa_urb_enqueue_run);
/*
* Process the errored transfers on the Wire Adapter outside of interrupt.
*/
void wa_process_errored_transfers_run(struct work_struct *ws)
{
struct wahc *wa = container_of(ws, struct wahc, xfer_error_work);
struct wa_xfer *xfer, *next;
LIST_HEAD(tmp_list);
pr_info("%s: Run delayed STALL processing.\n", __func__);
/* Create a copy of the wa->xfer_errored_list while holding the lock */
spin_lock_irq(&wa->xfer_list_lock);
list_cut_position(&tmp_list, &wa->xfer_errored_list,
wa->xfer_errored_list.prev);
spin_unlock_irq(&wa->xfer_list_lock);
/*
* run rpipe_clear_feature_stalled from temp list without list lock
* held.
*/
list_for_each_entry_safe(xfer, next, &tmp_list, list_node) {
struct usb_host_endpoint *ep;
unsigned long flags;
struct wa_rpipe *rpipe;
spin_lock_irqsave(&xfer->lock, flags);
ep = xfer->ep;
rpipe = ep->hcpriv;
spin_unlock_irqrestore(&xfer->lock, flags);
/* clear RPIPE feature stalled without holding a lock. */
rpipe_clear_feature_stalled(wa, ep);
/* complete the xfer. This removes it from the tmp list. */
wa_xfer_completion(xfer);
/* check for work. */
wa_xfer_delayed_run(rpipe);
}
}
EXPORT_SYMBOL_GPL(wa_process_errored_transfers_run);
/*
* Submit a transfer to the Wire Adapter in a delayed way
*
* The process of enqueuing involves possible sleeps() [see
* enqueue_b(), for the rpipe_get() and the mutex_lock()]. If we are
* in an atomic section, we defer the enqueue_b() call--else we call direct.
*
* @urb: We own a reference to it done by the HCI Linux USB stack that
* will be given up by calling usb_hcd_giveback_urb() or by
* returning error from this function -> ergo we don't have to
* refcount it.
*/
int wa_urb_enqueue(struct wahc *wa, struct usb_host_endpoint *ep,
struct urb *urb, gfp_t gfp)
{
int result;
struct device *dev = &wa->usb_iface->dev;
struct wa_xfer *xfer;
unsigned long my_flags;
unsigned cant_sleep = irqs_disabled() | in_atomic();
if ((urb->transfer_buffer == NULL)
&& (urb->sg == NULL)
&& !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
&& urb->transfer_buffer_length != 0) {
dev_err(dev, "BUG? urb %p: NULL xfer buffer & NODMA\n", urb);
dump_stack();
}
spin_lock_irqsave(&wa->xfer_list_lock, my_flags);
result = usb_hcd_link_urb_to_ep(&(wa->wusb->usb_hcd), urb);
spin_unlock_irqrestore(&wa->xfer_list_lock, my_flags);
if (result < 0)
goto error_link_urb;
result = -ENOMEM;
xfer = kzalloc(sizeof(*xfer), gfp);
if (xfer == NULL)
goto error_kmalloc;
result = -ENOENT;
if (urb->status != -EINPROGRESS) /* cancelled */
goto error_dequeued; /* before starting? */
wa_xfer_init(xfer);
xfer->wa = wa_get(wa);
xfer->urb = urb;
xfer->gfp = gfp;
xfer->ep = ep;
urb->hcpriv = xfer;
dev_dbg(dev, "xfer %p urb %p pipe 0x%02x [%d bytes] %s %s %s\n",
xfer, urb, urb->pipe, urb->transfer_buffer_length,
urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP ? "dma" : "nodma",
urb->pipe & USB_DIR_IN ? "inbound" : "outbound",
cant_sleep ? "deferred" : "inline");
if (cant_sleep) {
usb_get_urb(urb);
spin_lock_irqsave(&wa->xfer_list_lock, my_flags);
list_add_tail(&xfer->list_node, &wa->xfer_delayed_list);
spin_unlock_irqrestore(&wa->xfer_list_lock, my_flags);
queue_work(wusbd, &wa->xfer_enqueue_work);
} else {
result = wa_urb_enqueue_b(xfer);
if (result < 0) {
/*
* URB submit/enqueue failed. Clean up, return an
* error and do not run the callback. This avoids
* an infinite submit/complete loop.
*/
dev_err(dev, "%s: URB enqueue failed: %d\n",
__func__, result);
wa_put(xfer->wa);
wa_xfer_put(xfer);
spin_lock_irqsave(&wa->xfer_list_lock, my_flags);
usb_hcd_unlink_urb_from_ep(&(wa->wusb->usb_hcd), urb);
spin_unlock_irqrestore(&wa->xfer_list_lock, my_flags);
return result;
}
}
return 0;
error_dequeued:
kfree(xfer);
error_kmalloc:
spin_lock_irqsave(&wa->xfer_list_lock, my_flags);
usb_hcd_unlink_urb_from_ep(&(wa->wusb->usb_hcd), urb);
spin_unlock_irqrestore(&wa->xfer_list_lock, my_flags);
error_link_urb:
return result;
}
EXPORT_SYMBOL_GPL(wa_urb_enqueue);
/*
* Dequeue a URB and make sure uwb_hcd_giveback_urb() [completion
* handler] is called.
*
* Until a transfer goes successfully through wa_urb_enqueue() it
* needs to be dequeued with completion calling; when stuck in delayed
* or before wa_xfer_setup() is called, we need to do completion.
*
* not setup If there is no hcpriv yet, that means that that enqueue
* still had no time to set the xfer up. Because
* urb->status should be other than -EINPROGRESS,
* enqueue() will catch that and bail out.
*
* If the transfer has gone through setup, we just need to clean it
* up. If it has gone through submit(), we have to abort it [with an
* asynch request] and then make sure we cancel each segment.
*
*/
int wa_urb_dequeue(struct wahc *wa, struct urb *urb, int status)
{
unsigned long flags, flags2;
struct wa_xfer *xfer;
struct wa_seg *seg;
struct wa_rpipe *rpipe;
unsigned cnt, done = 0, xfer_abort_pending;
unsigned rpipe_ready = 0;
int result;
/* check if it is safe to unlink. */
spin_lock_irqsave(&wa->xfer_list_lock, flags);
result = usb_hcd_check_unlink_urb(&(wa->wusb->usb_hcd), urb, status);
if ((result == 0) && urb->hcpriv) {
/*
* Get a xfer ref to prevent a race with wa_xfer_giveback
* cleaning up the xfer while we are working with it.
*/
wa_xfer_get(urb->hcpriv);
}
spin_unlock_irqrestore(&wa->xfer_list_lock, flags);
if (result)
return result;
xfer = urb->hcpriv;
if (xfer == NULL)
return -ENOENT;
spin_lock_irqsave(&xfer->lock, flags);
pr_debug("%s: DEQUEUE xfer id 0x%08X\n", __func__, wa_xfer_id(xfer));
rpipe = xfer->ep->hcpriv;
if (rpipe == NULL) {
pr_debug("%s: xfer %p id 0x%08X has no RPIPE. %s",
__func__, xfer, wa_xfer_id(xfer),
"Probably already aborted.\n" );
result = -ENOENT;
goto out_unlock;
}
/*
* Check for done to avoid racing with wa_xfer_giveback and completing
* twice.
*/
if (__wa_xfer_is_done(xfer)) {
pr_debug("%s: xfer %p id 0x%08X already done.\n", __func__,
xfer, wa_xfer_id(xfer));
result = -ENOENT;
goto out_unlock;
}
/* Check the delayed list -> if there, release and complete */
spin_lock_irqsave(&wa->xfer_list_lock, flags2);
if (!list_empty(&xfer->list_node) && xfer->seg == NULL)
goto dequeue_delayed;
spin_unlock_irqrestore(&wa->xfer_list_lock, flags2);
if (xfer->seg == NULL) /* still hasn't reached */
goto out_unlock; /* setup(), enqueue_b() completes */
/* Ok, the xfer is in flight already, it's been setup and submitted.*/
xfer_abort_pending = __wa_xfer_abort(xfer) >= 0;
/*
* grab the rpipe->seg_lock here to prevent racing with
* __wa_xfer_delayed_run.
*/
spin_lock(&rpipe->seg_lock);
for (cnt = 0; cnt < xfer->segs; cnt++) {
seg = xfer->seg[cnt];
pr_debug("%s: xfer id 0x%08X#%d status = %d\n",
__func__, wa_xfer_id(xfer), cnt, seg->status);
switch (seg->status) {
case WA_SEG_NOTREADY:
case WA_SEG_READY:
printk(KERN_ERR "xfer %p#%u: dequeue bad state %u\n",
xfer, cnt, seg->status);
WARN_ON(1);
break;
case WA_SEG_DELAYED:
/*
* delete from rpipe delayed list. If no segments on
* this xfer have been submitted, __wa_xfer_is_done will
* trigger a giveback below. Otherwise, the submitted
* segments will be completed in the DTI interrupt.
*/
seg->status = WA_SEG_ABORTED;
seg->result = -ENOENT;
list_del(&seg->list_node);
xfer->segs_done++;
break;
case WA_SEG_DONE:
case WA_SEG_ERROR:
case WA_SEG_ABORTED:
break;
/*
* The buf_in data for a segment in the
* WA_SEG_DTI_PENDING state is actively being read.
* Let wa_buf_in_cb handle it since it will be called
* and will increment xfer->segs_done. Cleaning up
* here could cause wa_buf_in_cb to access the xfer
* after it has been completed/freed.
*/
case WA_SEG_DTI_PENDING:
break;
/*
* In the states below, the HWA device already knows
* about the transfer. If an abort request was sent,
* allow the HWA to process it and wait for the
* results. Otherwise, the DTI state and seg completed
* counts can get out of sync.
*/
case WA_SEG_SUBMITTED:
case WA_SEG_PENDING:
/*
* Check if the abort was successfully sent. This could
* be false if the HWA has been removed but we haven't
* gotten the disconnect notification yet.
*/
if (!xfer_abort_pending) {
seg->status = WA_SEG_ABORTED;
rpipe_ready = rpipe_avail_inc(rpipe);
xfer->segs_done++;
}
break;
}
}
spin_unlock(&rpipe->seg_lock);
xfer->result = urb->status; /* -ENOENT or -ECONNRESET */
done = __wa_xfer_is_done(xfer);
spin_unlock_irqrestore(&xfer->lock, flags);
if (done)
wa_xfer_completion(xfer);
if (rpipe_ready)
wa_xfer_delayed_run(rpipe);
wa_xfer_put(xfer);
return result;
out_unlock:
spin_unlock_irqrestore(&xfer->lock, flags);
wa_xfer_put(xfer);
return result;
dequeue_delayed:
list_del_init(&xfer->list_node);
spin_unlock_irqrestore(&wa->xfer_list_lock, flags2);
xfer->result = urb->status;
spin_unlock_irqrestore(&xfer->lock, flags);
wa_xfer_giveback(xfer);
wa_xfer_put(xfer);
usb_put_urb(urb); /* we got a ref in enqueue() */
return 0;
}
EXPORT_SYMBOL_GPL(wa_urb_dequeue);
/*
* Translation from WA status codes (WUSB1.0 Table 8.15) to errno
* codes
*
* Positive errno values are internal inconsistencies and should be
* flagged louder. Negative are to be passed up to the user in the
* normal way.
*
* @status: USB WA status code -- high two bits are stripped.
*/
static int wa_xfer_status_to_errno(u8 status)
{
int errno;
u8 real_status = status;
static int xlat[] = {
[WA_XFER_STATUS_SUCCESS] = 0,
[WA_XFER_STATUS_HALTED] = -EPIPE,
[WA_XFER_STATUS_DATA_BUFFER_ERROR] = -ENOBUFS,
[WA_XFER_STATUS_BABBLE] = -EOVERFLOW,
[WA_XFER_RESERVED] = EINVAL,
[WA_XFER_STATUS_NOT_FOUND] = 0,
[WA_XFER_STATUS_INSUFFICIENT_RESOURCE] = -ENOMEM,
[WA_XFER_STATUS_TRANSACTION_ERROR] = -EILSEQ,
[WA_XFER_STATUS_ABORTED] = -ENOENT,
[WA_XFER_STATUS_RPIPE_NOT_READY] = EINVAL,
[WA_XFER_INVALID_FORMAT] = EINVAL,
[WA_XFER_UNEXPECTED_SEGMENT_NUMBER] = EINVAL,
[WA_XFER_STATUS_RPIPE_TYPE_MISMATCH] = EINVAL,
};
status &= 0x3f;
if (status == 0)
return 0;
if (status >= ARRAY_SIZE(xlat)) {
printk_ratelimited(KERN_ERR "%s(): BUG? "
"Unknown WA transfer status 0x%02x\n",
__func__, real_status);
return -EINVAL;
}
errno = xlat[status];
if (unlikely(errno > 0)) {
printk_ratelimited(KERN_ERR "%s(): BUG? "
"Inconsistent WA status: 0x%02x\n",
__func__, real_status);
errno = -errno;
}
return errno;
}
/*
* If a last segment flag and/or a transfer result error is encountered,
* no other segment transfer results will be returned from the device.
* Mark the remaining submitted or pending xfers as completed so that
* the xfer will complete cleanly.
*
* xfer->lock must be held
*
*/
static void wa_complete_remaining_xfer_segs(struct wa_xfer *xfer,
int starting_index, enum wa_seg_status status)
{
int index;
struct wa_rpipe *rpipe = xfer->ep->hcpriv;
for (index = starting_index; index < xfer->segs_submitted; index++) {
struct wa_seg *current_seg = xfer->seg[index];
BUG_ON(current_seg == NULL);
switch (current_seg->status) {
case WA_SEG_SUBMITTED:
case WA_SEG_PENDING:
case WA_SEG_DTI_PENDING:
rpipe_avail_inc(rpipe);
/*
* do not increment RPIPE avail for the WA_SEG_DELAYED case
* since it has not been submitted to the RPIPE.
*/
case WA_SEG_DELAYED:
xfer->segs_done++;
current_seg->status = status;
break;
case WA_SEG_ABORTED:
break;
default:
WARN(1, "%s: xfer 0x%08X#%d. bad seg status = %d\n",
__func__, wa_xfer_id(xfer), index,
current_seg->status);
break;
}
}
}
/* Populate the given urb based on the current isoc transfer state. */
static int __wa_populate_buf_in_urb_isoc(struct wahc *wa,
struct urb *buf_in_urb, struct wa_xfer *xfer, struct wa_seg *seg)
{
int urb_start_frame = seg->isoc_frame_index + seg->isoc_frame_offset;
int seg_index, total_len = 0, urb_frame_index = urb_start_frame;
struct usb_iso_packet_descriptor *iso_frame_desc =
xfer->urb->iso_frame_desc;
const int dti_packet_size = usb_endpoint_maxp(wa->dti_epd);
int next_frame_contiguous;
struct usb_iso_packet_descriptor *iso_frame;
BUG_ON(buf_in_urb->status == -EINPROGRESS);
/*
* If the current frame actual_length is contiguous with the next frame
* and actual_length is a multiple of the DTI endpoint max packet size,
* combine the current frame with the next frame in a single URB. This
* reduces the number of URBs that must be submitted in that case.
*/
seg_index = seg->isoc_frame_index;
do {
next_frame_contiguous = 0;
iso_frame = &iso_frame_desc[urb_frame_index];
total_len += iso_frame->actual_length;
++urb_frame_index;
++seg_index;
if (seg_index < seg->isoc_frame_count) {
struct usb_iso_packet_descriptor *next_iso_frame;
next_iso_frame = &iso_frame_desc[urb_frame_index];
if ((iso_frame->offset + iso_frame->actual_length) ==
next_iso_frame->offset)
next_frame_contiguous = 1;
}
} while (next_frame_contiguous
&& ((iso_frame->actual_length % dti_packet_size) == 0));
/* this should always be 0 before a resubmit. */
buf_in_urb->num_mapped_sgs = 0;
buf_in_urb->transfer_dma = xfer->urb->transfer_dma +
iso_frame_desc[urb_start_frame].offset;
buf_in_urb->transfer_buffer_length = total_len;
buf_in_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
buf_in_urb->transfer_buffer = NULL;
buf_in_urb->sg = NULL;
buf_in_urb->num_sgs = 0;
buf_in_urb->context = seg;
/* return the number of frames included in this URB. */
return seg_index - seg->isoc_frame_index;
}
/* Populate the given urb based on the current transfer state. */
static int wa_populate_buf_in_urb(struct urb *buf_in_urb, struct wa_xfer *xfer,
unsigned int seg_idx, unsigned int bytes_transferred)
{
int result = 0;
struct wa_seg *seg = xfer->seg[seg_idx];
BUG_ON(buf_in_urb->status == -EINPROGRESS);
/* this should always be 0 before a resubmit. */
buf_in_urb->num_mapped_sgs = 0;
if (xfer->is_dma) {
buf_in_urb->transfer_dma = xfer->urb->transfer_dma
+ (seg_idx * xfer->seg_size);
buf_in_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
buf_in_urb->transfer_buffer = NULL;
buf_in_urb->sg = NULL;
buf_in_urb->num_sgs = 0;
} else {
/* do buffer or SG processing. */
buf_in_urb->transfer_flags &= ~URB_NO_TRANSFER_DMA_MAP;
if (xfer->urb->transfer_buffer) {
buf_in_urb->transfer_buffer =
xfer->urb->transfer_buffer
+ (seg_idx * xfer->seg_size);
buf_in_urb->sg = NULL;
buf_in_urb->num_sgs = 0;
} else {
/* allocate an SG list to store seg_size bytes
and copy the subset of the xfer->urb->sg
that matches the buffer subset we are
about to read. */
buf_in_urb->sg = wa_xfer_create_subset_sg(
xfer->urb->sg,
seg_idx * xfer->seg_size,
bytes_transferred,
&(buf_in_urb->num_sgs));
if (!(buf_in_urb->sg)) {
buf_in_urb->num_sgs = 0;
result = -ENOMEM;
}
buf_in_urb->transfer_buffer = NULL;
}
}
buf_in_urb->transfer_buffer_length = bytes_transferred;
buf_in_urb->context = seg;
return result;
}
/*
* Process a xfer result completion message
*
* inbound transfers: need to schedule a buf_in_urb read
*
* FIXME: this function needs to be broken up in parts
*/
static void wa_xfer_result_chew(struct wahc *wa, struct wa_xfer *xfer,
struct wa_xfer_result *xfer_result)
{
int result;
struct device *dev = &wa->usb_iface->dev;
unsigned long flags;
unsigned int seg_idx;
struct wa_seg *seg;
struct wa_rpipe *rpipe;
unsigned done = 0;
u8 usb_status;
unsigned rpipe_ready = 0;
unsigned bytes_transferred = le32_to_cpu(xfer_result->dwTransferLength);
struct urb *buf_in_urb = &(wa->buf_in_urbs[0]);
spin_lock_irqsave(&xfer->lock, flags);
seg_idx = xfer_result->bTransferSegment & 0x7f;
if (unlikely(seg_idx >= xfer->segs))
goto error_bad_seg;
seg = xfer->seg[seg_idx];
rpipe = xfer->ep->hcpriv;
usb_status = xfer_result->bTransferStatus;
dev_dbg(dev, "xfer %p ID 0x%08X#%u: bTransferStatus 0x%02x (seg status %u)\n",
xfer, wa_xfer_id(xfer), seg_idx, usb_status, seg->status);
if (seg->status == WA_SEG_ABORTED
|| seg->status == WA_SEG_ERROR) /* already handled */
goto segment_aborted;
if (seg->status == WA_SEG_SUBMITTED) /* ops, got here */
seg->status = WA_SEG_PENDING; /* before wa_seg{_dto}_cb() */
if (seg->status != WA_SEG_PENDING) {
if (printk_ratelimit())
dev_err(dev, "xfer %p#%u: Bad segment state %u\n",
xfer, seg_idx, seg->status);
seg->status = WA_SEG_PENDING; /* workaround/"fix" it */
}
if (usb_status & 0x80) {
seg->result = wa_xfer_status_to_errno(usb_status);
dev_err(dev, "DTI: xfer %p 0x%08X:#%u failed (0x%02x)\n",
xfer, xfer->id, seg->index, usb_status);
seg->status = ((usb_status & 0x7F) == WA_XFER_STATUS_ABORTED) ?
WA_SEG_ABORTED : WA_SEG_ERROR;
goto error_complete;
}
/* FIXME: we ignore warnings, tally them for stats */
if (usb_status & 0x40) /* Warning?... */
usb_status = 0; /* ... pass */
/*
* If the last segment bit is set, complete the remaining segments.
* When the current segment is completed, either in wa_buf_in_cb for
* transfers with data or below for no data, the xfer will complete.
*/
if (xfer_result->bTransferSegment & 0x80)
wa_complete_remaining_xfer_segs(xfer, seg->index + 1,
WA_SEG_DONE);
if (usb_pipeisoc(xfer->urb->pipe)
&& (le32_to_cpu(xfer_result->dwNumOfPackets) > 0)) {
/* set up WA state to read the isoc packet status next. */
wa->dti_isoc_xfer_in_progress = wa_xfer_id(xfer);
wa->dti_isoc_xfer_seg = seg_idx;
wa->dti_state = WA_DTI_ISOC_PACKET_STATUS_PENDING;
} else if (xfer->is_inbound && !usb_pipeisoc(xfer->urb->pipe)
&& (bytes_transferred > 0)) {
/* IN data phase: read to buffer */
seg->status = WA_SEG_DTI_PENDING;
result = wa_populate_buf_in_urb(buf_in_urb, xfer, seg_idx,
bytes_transferred);
if (result < 0)
goto error_buf_in_populate;
++(wa->active_buf_in_urbs);
result = usb_submit_urb(buf_in_urb, GFP_ATOMIC);
if (result < 0) {
--(wa->active_buf_in_urbs);
goto error_submit_buf_in;
}
} else {
/* OUT data phase or no data, complete it -- */
seg->result = bytes_transferred;
rpipe_ready = rpipe_avail_inc(rpipe);
done = __wa_xfer_mark_seg_as_done(xfer, seg, WA_SEG_DONE);
}
spin_unlock_irqrestore(&xfer->lock, flags);
if (done)
wa_xfer_completion(xfer);
if (rpipe_ready)
wa_xfer_delayed_run(rpipe);
return;
error_submit_buf_in:
if (edc_inc(&wa->dti_edc, EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
dev_err(dev, "DTI: URB max acceptable errors "
"exceeded, resetting device\n");
wa_reset_all(wa);
}
if (printk_ratelimit())
dev_err(dev, "xfer %p#%u: can't submit DTI data phase: %d\n",
xfer, seg_idx, result);
seg->result = result;
kfree(buf_in_urb->sg);
buf_in_urb->sg = NULL;
error_buf_in_populate:
__wa_xfer_abort(xfer);
seg->status = WA_SEG_ERROR;
error_complete:
xfer->segs_done++;
rpipe_ready = rpipe_avail_inc(rpipe);
wa_complete_remaining_xfer_segs(xfer, seg->index + 1, seg->status);
done = __wa_xfer_is_done(xfer);
/*
* queue work item to clear STALL for control endpoints.
* Otherwise, let endpoint_reset take care of it.
*/
if (((usb_status & 0x3f) == WA_XFER_STATUS_HALTED) &&
usb_endpoint_xfer_control(&xfer->ep->desc) &&
done) {
dev_info(dev, "Control EP stall. Queue delayed work.\n");
spin_lock(&wa->xfer_list_lock);
/* move xfer from xfer_list to xfer_errored_list. */
list_move_tail(&xfer->list_node, &wa->xfer_errored_list);
spin_unlock(&wa->xfer_list_lock);
spin_unlock_irqrestore(&xfer->lock, flags);
queue_work(wusbd, &wa->xfer_error_work);
} else {
spin_unlock_irqrestore(&xfer->lock, flags);
if (done)
wa_xfer_completion(xfer);
if (rpipe_ready)
wa_xfer_delayed_run(rpipe);
}
return;
error_bad_seg:
spin_unlock_irqrestore(&xfer->lock, flags);
wa_urb_dequeue(wa, xfer->urb, -ENOENT);
if (printk_ratelimit())
dev_err(dev, "xfer %p#%u: bad segment\n", xfer, seg_idx);
if (edc_inc(&wa->dti_edc, EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
dev_err(dev, "DTI: URB max acceptable errors "
"exceeded, resetting device\n");
wa_reset_all(wa);
}
return;
segment_aborted:
/* nothing to do, as the aborter did the completion */
spin_unlock_irqrestore(&xfer->lock, flags);
}
/*
* Process a isochronous packet status message
*
* inbound transfers: need to schedule a buf_in_urb read
*/
static int wa_process_iso_packet_status(struct wahc *wa, struct urb *urb)
{
struct device *dev = &wa->usb_iface->dev;
struct wa_xfer_packet_status_hwaiso *packet_status;
struct wa_xfer_packet_status_len_hwaiso *status_array;
struct wa_xfer *xfer;
unsigned long flags;
struct wa_seg *seg;
struct wa_rpipe *rpipe;
unsigned done = 0, dti_busy = 0, data_frame_count = 0, seg_index;
unsigned first_frame_index = 0, rpipe_ready = 0;
int expected_size;
/* We have a xfer result buffer; check it */
dev_dbg(dev, "DTI: isoc packet status %d bytes at %p\n",
urb->actual_length, urb->transfer_buffer);
packet_status = (struct wa_xfer_packet_status_hwaiso *)(wa->dti_buf);
if (packet_status->bPacketType != WA_XFER_ISO_PACKET_STATUS) {
dev_err(dev, "DTI Error: isoc packet status--bad type 0x%02x\n",
packet_status->bPacketType);
goto error_parse_buffer;
}
xfer = wa_xfer_get_by_id(wa, wa->dti_isoc_xfer_in_progress);
if (xfer == NULL) {
dev_err(dev, "DTI Error: isoc packet status--unknown xfer 0x%08x\n",
wa->dti_isoc_xfer_in_progress);
goto error_parse_buffer;
}
spin_lock_irqsave(&xfer->lock, flags);
if (unlikely(wa->dti_isoc_xfer_seg >= xfer->segs))
goto error_bad_seg;
seg = xfer->seg[wa->dti_isoc_xfer_seg];
rpipe = xfer->ep->hcpriv;
expected_size = sizeof(*packet_status) +
(sizeof(packet_status->PacketStatus[0]) *
seg->isoc_frame_count);
if (urb->actual_length != expected_size) {
dev_err(dev, "DTI Error: isoc packet status--bad urb length (%d bytes vs %d needed)\n",
urb->actual_length, expected_size);
goto error_bad_seg;
}
if (le16_to_cpu(packet_status->wLength) != expected_size) {
dev_err(dev, "DTI Error: isoc packet status--bad length %u\n",
le16_to_cpu(packet_status->wLength));
goto error_bad_seg;
}
/* write isoc packet status and lengths back to the xfer urb. */
status_array = packet_status->PacketStatus;
xfer->urb->start_frame =
wa->wusb->usb_hcd.driver->get_frame_number(&wa->wusb->usb_hcd);
for (seg_index = 0; seg_index < seg->isoc_frame_count; ++seg_index) {
struct usb_iso_packet_descriptor *iso_frame_desc =
xfer->urb->iso_frame_desc;
const int xfer_frame_index =
seg->isoc_frame_offset + seg_index;
iso_frame_desc[xfer_frame_index].status =
wa_xfer_status_to_errno(
le16_to_cpu(status_array[seg_index].PacketStatus));
iso_frame_desc[xfer_frame_index].actual_length =
le16_to_cpu(status_array[seg_index].PacketLength);
/* track the number of frames successfully transferred. */
if (iso_frame_desc[xfer_frame_index].actual_length > 0) {
/* save the starting frame index for buf_in_urb. */
if (!data_frame_count)
first_frame_index = seg_index;
++data_frame_count;
}
}
if (xfer->is_inbound && data_frame_count) {
int result, total_frames_read = 0, urb_index = 0;
struct urb *buf_in_urb;
/* IN data phase: read to buffer */
seg->status = WA_SEG_DTI_PENDING;
/* start with the first frame with data. */
seg->isoc_frame_index = first_frame_index;
/* submit up to WA_MAX_BUF_IN_URBS read URBs. */
do {
int urb_frame_index, urb_frame_count;
struct usb_iso_packet_descriptor *iso_frame_desc;
buf_in_urb = &(wa->buf_in_urbs[urb_index]);
urb_frame_count = __wa_populate_buf_in_urb_isoc(wa,
buf_in_urb, xfer, seg);
/* advance frame index to start of next read URB. */
seg->isoc_frame_index += urb_frame_count;
total_frames_read += urb_frame_count;
++(wa->active_buf_in_urbs);
result = usb_submit_urb(buf_in_urb, GFP_ATOMIC);
/* skip 0-byte frames. */
urb_frame_index =
seg->isoc_frame_offset + seg->isoc_frame_index;
iso_frame_desc =
&(xfer->urb->iso_frame_desc[urb_frame_index]);
while ((seg->isoc_frame_index <
seg->isoc_frame_count) &&
(iso_frame_desc->actual_length == 0)) {
++(seg->isoc_frame_index);
++iso_frame_desc;
}
++urb_index;
} while ((result == 0) && (urb_index < WA_MAX_BUF_IN_URBS)
&& (seg->isoc_frame_index <
seg->isoc_frame_count));
if (result < 0) {
--(wa->active_buf_in_urbs);
dev_err(dev, "DTI Error: Could not submit buf in URB (%d)",
result);
wa_reset_all(wa);
} else if (data_frame_count > total_frames_read)
/* If we need to read more frames, set DTI busy. */
dti_busy = 1;
} else {
/* OUT transfer or no more IN data, complete it -- */
rpipe_ready = rpipe_avail_inc(rpipe);
done = __wa_xfer_mark_seg_as_done(xfer, seg, WA_SEG_DONE);
}
spin_unlock_irqrestore(&xfer->lock, flags);
if (dti_busy)
wa->dti_state = WA_DTI_BUF_IN_DATA_PENDING;
else
wa->dti_state = WA_DTI_TRANSFER_RESULT_PENDING;
if (done)
wa_xfer_completion(xfer);
if (rpipe_ready)
wa_xfer_delayed_run(rpipe);
wa_xfer_put(xfer);
return dti_busy;
error_bad_seg:
spin_unlock_irqrestore(&xfer->lock, flags);
wa_xfer_put(xfer);
error_parse_buffer:
return dti_busy;
}
/*
* Callback for the IN data phase
*
* If successful transition state; otherwise, take a note of the
* error, mark this segment done and try completion.
*
* Note we don't access until we are sure that the transfer hasn't
* been cancelled (ECONNRESET, ENOENT), which could mean that
* seg->xfer could be already gone.
*/
static void wa_buf_in_cb(struct urb *urb)
{
struct wa_seg *seg = urb->context;
struct wa_xfer *xfer = seg->xfer;
struct wahc *wa;
struct device *dev;
struct wa_rpipe *rpipe;
unsigned rpipe_ready = 0, isoc_data_frame_count = 0;
unsigned long flags;
int resubmit_dti = 0, active_buf_in_urbs;
u8 done = 0;
/* free the sg if it was used. */
kfree(urb->sg);
urb->sg = NULL;
spin_lock_irqsave(&xfer->lock, flags);
wa = xfer->wa;
dev = &wa->usb_iface->dev;
--(wa->active_buf_in_urbs);
active_buf_in_urbs = wa->active_buf_in_urbs;
rpipe = xfer->ep->hcpriv;
if (usb_pipeisoc(xfer->urb->pipe)) {
struct usb_iso_packet_descriptor *iso_frame_desc =
xfer->urb->iso_frame_desc;
int seg_index;
/*
* Find the next isoc frame with data and count how many
* frames with data remain.
*/
seg_index = seg->isoc_frame_index;
while (seg_index < seg->isoc_frame_count) {
const int urb_frame_index =
seg->isoc_frame_offset + seg_index;
if (iso_frame_desc[urb_frame_index].actual_length > 0) {
/* save the index of the next frame with data */
if (!isoc_data_frame_count)
seg->isoc_frame_index = seg_index;
++isoc_data_frame_count;
}
++seg_index;
}
}
spin_unlock_irqrestore(&xfer->lock, flags);
switch (urb->status) {
case 0:
spin_lock_irqsave(&xfer->lock, flags);
seg->result += urb->actual_length;
if (isoc_data_frame_count > 0) {
int result, urb_frame_count;
/* submit a read URB for the next frame with data. */
urb_frame_count = __wa_populate_buf_in_urb_isoc(wa, urb,
xfer, seg);
/* advance index to start of next read URB. */
seg->isoc_frame_index += urb_frame_count;
++(wa->active_buf_in_urbs);
result = usb_submit_urb(urb, GFP_ATOMIC);
if (result < 0) {
--(wa->active_buf_in_urbs);
dev_err(dev, "DTI Error: Could not submit buf in URB (%d)",
result);
wa_reset_all(wa);
}
/*
* If we are in this callback and
* isoc_data_frame_count > 0, it means that the dti_urb
* submission was delayed in wa_dti_cb. Once
* we submit the last buf_in_urb, we can submit the
* delayed dti_urb.
*/
resubmit_dti = (isoc_data_frame_count ==
urb_frame_count);
} else if (active_buf_in_urbs == 0) {
dev_dbg(dev,
"xfer %p 0x%08X#%u: data in done (%zu bytes)\n",
xfer, wa_xfer_id(xfer), seg->index,
seg->result);
rpipe_ready = rpipe_avail_inc(rpipe);
done = __wa_xfer_mark_seg_as_done(xfer, seg,
WA_SEG_DONE);
}
spin_unlock_irqrestore(&xfer->lock, flags);
if (done)
wa_xfer_completion(xfer);
if (rpipe_ready)
wa_xfer_delayed_run(rpipe);
break;
case -ECONNRESET: /* URB unlinked; no need to do anything */
case -ENOENT: /* as it was done by the who unlinked us */
break;
default: /* Other errors ... */
/*
* Error on data buf read. Only resubmit DTI if it hasn't
* already been done by previously hitting this error or by a
* successful completion of the previous buf_in_urb.
*/
resubmit_dti = wa->dti_state != WA_DTI_TRANSFER_RESULT_PENDING;
spin_lock_irqsave(&xfer->lock, flags);
if (printk_ratelimit())
dev_err(dev, "xfer %p 0x%08X#%u: data in error %d\n",
xfer, wa_xfer_id(xfer), seg->index,
urb->status);
if (edc_inc(&wa->nep_edc, EDC_MAX_ERRORS,
EDC_ERROR_TIMEFRAME)){
dev_err(dev, "DTO: URB max acceptable errors "
"exceeded, resetting device\n");
wa_reset_all(wa);
}
seg->result = urb->status;
rpipe_ready = rpipe_avail_inc(rpipe);
if (active_buf_in_urbs == 0)
done = __wa_xfer_mark_seg_as_done(xfer, seg,
WA_SEG_ERROR);
else
__wa_xfer_abort(xfer);
spin_unlock_irqrestore(&xfer->lock, flags);
if (done)
wa_xfer_completion(xfer);
if (rpipe_ready)
wa_xfer_delayed_run(rpipe);
}
if (resubmit_dti) {
int result;
wa->dti_state = WA_DTI_TRANSFER_RESULT_PENDING;
result = usb_submit_urb(wa->dti_urb, GFP_ATOMIC);
if (result < 0) {
dev_err(dev, "DTI Error: Could not submit DTI URB (%d)\n",
result);
wa_reset_all(wa);
}
}
}
/*
* Handle an incoming transfer result buffer
*
* Given a transfer result buffer, it completes the transfer (possibly
* scheduling and buffer in read) and then resubmits the DTI URB for a
* new transfer result read.
*
*
* The xfer_result DTI URB state machine
*
* States: OFF | RXR (Read-Xfer-Result) | RBI (Read-Buffer-In)
*
* We start in OFF mode, the first xfer_result notification [through
* wa_handle_notif_xfer()] moves us to RXR by posting the DTI-URB to
* read.
*
* We receive a buffer -- if it is not a xfer_result, we complain and
* repost the DTI-URB. If it is a xfer_result then do the xfer seg
* request accounting. If it is an IN segment, we move to RBI and post
* a BUF-IN-URB to the right buffer. The BUF-IN-URB callback will
* repost the DTI-URB and move to RXR state. if there was no IN
* segment, it will repost the DTI-URB.
*
* We go back to OFF when we detect a ENOENT or ESHUTDOWN (or too many
* errors) in the URBs.
*/
static void wa_dti_cb(struct urb *urb)
{
int result, dti_busy = 0;
struct wahc *wa = urb->context;
struct device *dev = &wa->usb_iface->dev;
u32 xfer_id;
u8 usb_status;
BUG_ON(wa->dti_urb != urb);