patch "xhci: handle no ping response error properly" added to usb-linus

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    xhci: handle no ping response error properly

to my usb git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.

If you have any questions about this process, please let me know.


>From 3b4739b8951d650becbcd855d7d6f18ac98a9a85 Mon Sep 17 00:00:00 2001
From: Mathias Nyman <mathias.nyman@linux.intel.com>
Date: Mon, 12 Oct 2015 11:30:12 +0300
Subject: xhci: handle no ping response error properly

If a host fails to wake up a isochronous SuperSpeed device from U1/U2
in time for a isoch transfer it will generate a "No ping response error"
Host will then move to the next transfer descriptor.

Handle this case in the same way as missed service errors, tag the
current TD as skipped and handle it on the next transfer event.

Cc: stable <stable@vger.kernel.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/host/xhci-ring.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 79e89e6aef73..97ffe3997273 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -2284,6 +2284,7 @@ static int handle_tx_event(struct xhci_hcd *xhci,
 	u32 trb_comp_code;
 	int ret = 0;
 	int td_num = 0;
+	bool handling_skipped_tds = false;
 
 	slot_id = TRB_TO_SLOT_ID(le32_to_cpu(event->flags));
 	xdev = xhci->devs[slot_id];
@@ -2420,6 +2421,10 @@ static int handle_tx_event(struct xhci_hcd *xhci,
 		ep->skip = true;
 		xhci_dbg(xhci, "Miss service interval error, set skip flag\n");
 		goto cleanup;
+	case COMP_PING_ERR:
+		ep->skip = true;
+		xhci_dbg(xhci, "No Ping response error, Skip one Isoc TD\n");
+		goto cleanup;
 	default:
 		if (xhci_is_vendor_info_code(xhci, trb_comp_code)) {
 			status = 0;
@@ -2556,13 +2561,18 @@ static int handle_tx_event(struct xhci_hcd *xhci,
 						 ep, &status);
 
 cleanup:
+
+
+		handling_skipped_tds = ep->skip &&
+			trb_comp_code != COMP_MISSED_INT &&
+			trb_comp_code != COMP_PING_ERR;
+
 		/*
-		 * Do not update event ring dequeue pointer if ep->skip is set.
-		 * Will roll back to continue process missed tds.
+		 * Do not update event ring dequeue pointer if we're in a loop
+		 * processing missed tds.
 		 */
-		if (trb_comp_code == COMP_MISSED_INT || !ep->skip) {
+		if (!handling_skipped_tds)
 			inc_deq(xhci, xhci->event_ring);
-		}
 
 		if (ret) {
 			urb = td->urb;
@@ -2597,7 +2607,7 @@ cleanup:
 	 * Process them as short transfer until reach the td pointed by
 	 * the event.
 	 */
-	} while (ep->skip && trb_comp_code != COMP_MISSED_INT);
+	} while (handling_skipped_tds);
 
 	return 0;
 }
-- 
2.6.1