| From 710bf937ca93632f2a7e7a7c6a9068c1ff4e4e44 Mon Sep 17 00:00:00 2001 |
| From: Steve Glendinning <steve.glendinning@smsc.com> |
| Date: Tue, 22 Sep 2009 04:00:27 +0000 |
| Subject: smsc95xx: fix transmission where ZLP is expected |
| |
| From: Steve Glendinning <steve.glendinning@smsc.com> |
| |
| [ Upstream commit ec4756238239f1a331d9fb95bad8b281dad56855 ] |
| |
| Usbnet framework assumes USB hardware doesn't handle zero length |
| packets, but SMSC LAN95xx requires these to be sent for correct |
| operation. |
| |
| This patch fixes an easily reproducible tx lockup when sending a frame |
| that results in exactly 512 bytes in a USB transmission (e.g. a UDP |
| frame with 458 data bytes, due to IP headers and our USB headers). It |
| adds an extra flag to usbnet for the hardware driver to indicate that |
| it can handle and requires the zero length packets. |
| |
| This patch should not affect other usbnet users, please also consider |
| for -stable. |
| |
| Signed-off-by: Steve Glendinning <steve.glendinning@smsc.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| --- |
| drivers/net/usb/smsc95xx.c | 2 +- |
| drivers/net/usb/usbnet.c | 2 +- |
| include/linux/usb/usbnet.h | 1 + |
| 3 files changed, 3 insertions(+), 2 deletions(-) |
| |
| --- a/drivers/net/usb/smsc95xx.c |
| +++ b/drivers/net/usb/smsc95xx.c |
| @@ -1232,7 +1232,7 @@ static const struct driver_info smsc95xx |
| .rx_fixup = smsc95xx_rx_fixup, |
| .tx_fixup = smsc95xx_tx_fixup, |
| .status = smsc95xx_status, |
| - .flags = FLAG_ETHER, |
| + .flags = FLAG_ETHER | FLAG_SEND_ZLP, |
| }; |
| |
| static const struct usb_device_id products[] = { |
| --- a/drivers/net/usb/usbnet.c |
| +++ b/drivers/net/usb/usbnet.c |
| @@ -988,7 +988,7 @@ int usbnet_start_xmit (struct sk_buff *s |
| * NOTE: strictly conforming cdc-ether devices should expect |
| * the ZLP here, but ignore the one-byte packet. |
| */ |
| - if ((length % dev->maxpacket) == 0) { |
| + if (!(info->flags & FLAG_SEND_ZLP) && (length % dev->maxpacket) == 0) { |
| urb->transfer_buffer_length++; |
| if (skb_tailroom(skb)) { |
| skb->data[skb->len] = 0; |
| --- a/include/linux/usb/usbnet.h |
| +++ b/include/linux/usb/usbnet.h |
| @@ -86,6 +86,7 @@ struct driver_info { |
| |
| #define FLAG_FRAMING_AX 0x0040 /* AX88772/178 packets */ |
| #define FLAG_WLAN 0x0080 /* use "wlan%d" names */ |
| +#define FLAG_SEND_ZLP 0x0200 /* hw requires ZLPs are sent */ |
| |
| |
| /* init device ... can sleep, or cause probe() failure */ |
