This is a note to let you know that I've just added the patch titled
xhci: Fix giving back cancelled URBs even if halted endpoint can't reset
to the 5.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
xhci-fix-giving-back-cancelled-urbs-even-if-halted-endpoint-can-t-reset.patch
and it can be found in the queue-5.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 9b6a126ae58d9edfdde2d5f2e87f7615ea5e0155 Mon Sep 17 00:00:00 2001
From: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Date: Wed, 12 May 2021 11:08:13 +0300
Subject: xhci: Fix giving back cancelled URBs even if halted endpoint can't reset
From: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
commit 9b6a126ae58d9edfdde2d5f2e87f7615ea5e0155 upstream.
Commit 9ebf30007858 ("xhci: Fix halted endpoint at stop endpoint command
completion") in 5.12 changes how cancelled URBs are given back.
To cancel a URB xhci driver needs to stop the endpoint first.
To clear a halted endpoint xhci driver needs to reset the endpoint.
In rare cases when an endpoint halt (error) races with a endpoint stop we
need to clear the reset before removing, and giving back the cancelled URB.
The above change in 5.12 takes care of this, but it also relies on the
reset endpoint completion handler to give back the cancelled URBs.
There are cases when driver refuses to queue reset endpoint commands,
for example when a link suddenly goes to an inactive error state.
In this case the cancelled URB is never given back.
Fix this by giving back the URB in the stop endpoint if queuing a reset
endpoint command fails.
Fixes: 9ebf30007858 ("xhci: Fix halted endpoint at stop endpoint command completion")
CC: <stable@xxxxxxxxxxxxxxx> # 5.12
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210512080816.866037-3-mathias.nyman@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/host/xhci-ring.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -863,7 +863,7 @@ done:
return ret;
}
-static void xhci_handle_halted_endpoint(struct xhci_hcd *xhci,
+static int xhci_handle_halted_endpoint(struct xhci_hcd *xhci,
struct xhci_virt_ep *ep, unsigned int stream_id,
struct xhci_td *td,
enum xhci_ep_reset_type reset_type)
@@ -876,7 +876,7 @@ static void xhci_handle_halted_endpoint(
* Device will be reset soon to recover the link so don't do anything
*/
if (ep->vdev->flags & VDEV_PORT_ERROR)
- return;
+ return -ENODEV;
/* add td to cancelled list and let reset ep handler take care of it */
if (reset_type == EP_HARD_RESET) {
@@ -889,16 +889,18 @@ static void xhci_handle_halted_endpoint(
if (ep->ep_state & EP_HALTED) {
xhci_dbg(xhci, "Reset ep command already pending\n");
- return;
+ return 0;
}
err = xhci_reset_halted_ep(xhci, slot_id, ep->ep_index, reset_type);
if (err)
- return;
+ return err;
ep->ep_state |= EP_HALTED;
xhci_ring_cmd_db(xhci);
+
+ return 0;
}
/*
@@ -1015,6 +1017,7 @@ static void xhci_handle_cmd_stop_ep(stru
struct xhci_td *td = NULL;
enum xhci_ep_reset_type reset_type;
struct xhci_command *command;
+ int err;
if (unlikely(TRB_TO_SUSPEND_PORT(le32_to_cpu(trb->generic.field[3])))) {
if (!xhci->devs[slot_id])
@@ -1059,7 +1062,10 @@ static void xhci_handle_cmd_stop_ep(stru
td->status = -EPROTO;
}
/* reset ep, reset handler cleans up cancelled tds */
- xhci_handle_halted_endpoint(xhci, ep, 0, td, reset_type);
+ err = xhci_handle_halted_endpoint(xhci, ep, 0, td,
+ reset_type);
+ if (err)
+ break;
xhci_stop_watchdog_timer_in_irq(xhci, ep);
return;
case EP_STATE_RUNNING:
Patches currently in stable-queue which might be from mathias.nyman@xxxxxxxxxxxxxxx are
queue-5.12/xhci-pci-allow-host-runtime-pm-as-default-for-intel-alder-lake-xhci.patch
queue-5.12/usb-xhci-increase-timeout-for-hc-halt.patch
queue-5.12/xhci-add-reset-resume-quirk-for-amd-xhci-controller.patch
queue-5.12/xhci-fix-giving-back-cancelled-urbs-even-if-halted-endpoint-can-t-reset.patch
queue-5.12/xhci-do-not-use-gfp_kernel-in-potentially-atomic-context.patch
