releases/3.0.50/xhci-handle-command-after-aborting-the-command-ring.patch

---
 drivers/usb/host/xhci-ring.c |  171 +++++++++++++++++++++++++++++++++++++++++--
 drivers/usb/host/xhci.h      |    3 
 2 files changed, 168 insertions(+), 6 deletions(-)

--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1157,6 +1157,20 @@ static void handle_reset_ep_completion(s
 	}
 }
 
+/* Complete the command and detele it from the devcie's command queue.
+ */
+static void xhci_complete_cmd_in_cmd_wait_list(struct xhci_hcd *xhci,
+		struct xhci_command *command, u32 status)
+{
+	command->status = status;
+	list_del(&command->cmd_list);
+	if (command->completion)
+		complete(command->completion);
+	else
+		xhci_free_command(xhci, command);
+}
+
+
 /* Check to see if a command in the device's command queue matches this one.
  * Signal the completion or free the command, and return 1.  Return 0 if the
  * completed command isn't at the head of the command list.
@@ -1175,15 +1189,144 @@ static int handle_cmd_in_cmd_wait_list(s
 	if (xhci->cmd_ring->dequeue != command->command_trb)
 		return 0;
 
-	command->status = GET_COMP_CODE(le32_to_cpu(event->status));
-	list_del(&command->cmd_list);
-	if (command->completion)
-		complete(command->completion);
-	else
-		xhci_free_command(xhci, command);
+	xhci_complete_cmd_in_cmd_wait_list(xhci, command,
+			GET_COMP_CODE(le32_to_cpu(event->status)));
 	return 1;
 }
 
+/*
+ * Finding the command trb need to be cancelled and modifying it to
+ * NO OP command. And if the command is in device's command wait
+ * list, finishing and freeing it.
+ *
+ * If we can't find the command trb, we think it had already been
+ * executed.
+ */
+static void xhci_cmd_to_noop(struct xhci_hcd *xhci, struct xhci_cd *cur_cd)
+{
+	struct xhci_segment *cur_seg;
+	union xhci_trb *cmd_trb;
+	u32 cycle_state;
+
+	if (xhci->cmd_ring->dequeue == xhci->cmd_ring->enqueue)
+		return;
+
+	/* find the current segment of command ring */
+	cur_seg = find_trb_seg(xhci->cmd_ring->first_seg,
+			xhci->cmd_ring->dequeue, &cycle_state);
+
+	/* find the command trb matched by cd from command ring */
+	for (cmd_trb = xhci->cmd_ring->dequeue;
+			cmd_trb != xhci->cmd_ring->enqueue;
+			next_trb(xhci, xhci->cmd_ring, &cur_seg, &cmd_trb)) {
+		/* If the trb is link trb, continue */
+		if (TRB_TYPE_LINK_LE32(cmd_trb->generic.field[3]))
+			continue;
+
+		if (cur_cd->cmd_trb == cmd_trb) {
+
+			/* If the command in device's command list, we should
+			 * finish it and free the command structure.
+			 */
+			if (cur_cd->command)
+				xhci_complete_cmd_in_cmd_wait_list(xhci,
+					cur_cd->command, COMP_CMD_STOP);
+
+			/* get cycle state from the origin command trb */
+			cycle_state = le32_to_cpu(cmd_trb->generic.field[3])
+				& TRB_CYCLE;
+
+			/* modify the command trb to NO OP command */
+			cmd_trb->generic.field[0] = 0;
+			cmd_trb->generic.field[1] = 0;
+			cmd_trb->generic.field[2] = 0;
+			cmd_trb->generic.field[3] = cpu_to_le32(
+					TRB_TYPE(TRB_CMD_NOOP) | cycle_state);
+			break;
+		}
+	}
+}
+
+static void xhci_cancel_cmd_in_cd_list(struct xhci_hcd *xhci)
+{
+	struct xhci_cd *cur_cd, *next_cd;
+
+	if (list_empty(&xhci->cancel_cmd_list))
+		return;
+
+	list_for_each_entry_safe(cur_cd, next_cd,
+			&xhci->cancel_cmd_list, cancel_cmd_list) {
+		xhci_cmd_to_noop(xhci, cur_cd);
+		list_del(&cur_cd->cancel_cmd_list);
+		kfree(cur_cd);
+	}
+}
+
+/*
+ * traversing the cancel_cmd_list. If the command descriptor according
+ * to cmd_trb is found, the function free it and return 1, otherwise
+ * return 0.
+ */
+static int xhci_search_cmd_trb_in_cd_list(struct xhci_hcd *xhci,
+		union xhci_trb *cmd_trb)
+{
+	struct xhci_cd *cur_cd, *next_cd;
+
+	if (list_empty(&xhci->cancel_cmd_list))
+		return 0;
+
+	list_for_each_entry_safe(cur_cd, next_cd,
+			&xhci->cancel_cmd_list, cancel_cmd_list) {
+		if (cur_cd->cmd_trb == cmd_trb) {
+			if (cur_cd->command)
+				xhci_complete_cmd_in_cmd_wait_list(xhci,
+					cur_cd->command, COMP_CMD_STOP);
+			list_del(&cur_cd->cancel_cmd_list);
+			kfree(cur_cd);
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * If the cmd_trb_comp_code is COMP_CMD_ABORT, we just check whether the
+ * trb pointed by the command ring dequeue pointer is the trb we want to
+ * cancel or not. And if the cmd_trb_comp_code is COMP_CMD_STOP, we will
+ * traverse the cancel_cmd_list to trun the all of the commands according
+ * to command descriptor to NO-OP trb.
+ */
+static int handle_stopped_cmd_ring(struct xhci_hcd *xhci,
+		int cmd_trb_comp_code)
+{
+	int cur_trb_is_good = 0;
+
+	/* Searching the cmd trb pointed by the command ring dequeue
+	 * pointer in command descriptor list. If it is found, free it.
+	 */
+	cur_trb_is_good = xhci_search_cmd_trb_in_cd_list(xhci,
+			xhci->cmd_ring->dequeue);
+
+	if (cmd_trb_comp_code == COMP_CMD_ABORT)
+		xhci->cmd_ring_state = CMD_RING_STATE_STOPPED;
+	else if (cmd_trb_comp_code == COMP_CMD_STOP) {
+		/* traversing the cancel_cmd_list and canceling
+		 * the command according to command descriptor
+		 */
+		xhci_cancel_cmd_in_cd_list(xhci);
+
+		xhci->cmd_ring_state = CMD_RING_STATE_RUNNING;
+		/*
+		 * ring command ring doorbell again to restart the
+		 * command ring
+		 */
+		if (xhci->cmd_ring->dequeue != xhci->cmd_ring->enqueue)
+			xhci_ring_cmd_db(xhci);
+	}
+	return cur_trb_is_good;
+}
+
 static void handle_cmd_completion(struct xhci_hcd *xhci,
 		struct xhci_event_cmd *event)
 {
@@ -1209,6 +1352,22 @@ static void handle_cmd_completion(struct
 		xhci->error_bitmask |= 1 << 5;
 		return;
 	}
+
+	if ((GET_COMP_CODE(le32_to_cpu(event->status)) == COMP_CMD_ABORT) ||
+		(GET_COMP_CODE(le32_to_cpu(event->status)) == COMP_CMD_STOP)) {
+		/* If the return value is 0, we think the trb pointed by
+		 * command ring dequeue pointer is a good trb. The good
+		 * trb means we don't want to cancel the trb, but it have
+		 * been stopped by host. So we should handle it normally.
+		 * Otherwise, driver should invoke inc_deq() and return.
+		 */
+		if (handle_stopped_cmd_ring(xhci,
+				GET_COMP_CODE(le32_to_cpu(event->status)))) {
+			inc_deq(xhci, xhci->cmd_ring, false);
+			return;
+		}
+	}
+
 	switch (le32_to_cpu(xhci->cmd_ring->dequeue->generic.field[3])
 		& TRB_TYPE_BITMASK) {
 	case TRB_TYPE(TRB_ENABLE_SLOT):
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1070,6 +1070,9 @@ union xhci_trb {
 #define TRB_MFINDEX_WRAP	39
 /* TRB IDs 40-47 reserved, 48-63 is vendor-defined */
 
+#define TRB_TYPE_LINK_LE32(x)   (((x) & cpu_to_le32(TRB_TYPE_BITMASK)) == \
+		cpu_to_le32(TRB_TYPE(TRB_LINK)))
+
 /* Nec vendor-specific command completion event. */
 #define	TRB_NEC_CMD_COMP	48
 /* Get NEC firmware revision. */