patch "xhci: Always restore EP_SOFT_CLEAR_TOGGLE even if ep reset failed" added to usb-linus

[<gregkh@linuxfoundation.org>]

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

    xhci: Always restore EP_SOFT_CLEAR_TOGGLE even if ep reset failed

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 f1ec7ae6c9f8c016db320e204cb519a1da1581b8 Mon Sep 17 00:00:00 2001
From: Ding Hui <dinghui@sangfor.com.cn>
Date: Fri, 21 Aug 2020 12:15:49 +0300
Subject: xhci: Always restore EP_SOFT_CLEAR_TOGGLE even if ep reset failed

Some device drivers call libusb_clear_halt when target ep queue
is not empty. (eg. spice client connected to qemu for usb redir)

Before commit f5249461b504 ("xhci: Clear the host side toggle
manually when endpoint is soft reset"), that works well.
But now, we got the error log:

    EP not empty, refuse reset

xhci_endpoint_reset failed and left ep_state's EP_SOFT_CLEAR_TOGGLE
bit still set

So all the subsequent urb sumbits to the ep will fail with the
warn log:

    Can't enqueue URB while manually clearing toggle

We need to clear ep_state EP_SOFT_CLEAR_TOGGLE bit after
xhci_endpoint_reset, even if it failed.

Fixes: f5249461b504 ("xhci: Clear the host side toggle manually when endpoint is soft reset")
Cc: stable <stable@vger.kernel.org> # v4.17+
Signed-off-by: Ding Hui <dinghui@sangfor.com.cn>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20200821091549.20556-4-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/host/xhci.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 3c41b14ecce7..e9884ae9c77d 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -3236,10 +3236,11 @@ static void xhci_endpoint_reset(struct usb_hcd *hcd,
 
 	wait_for_completion(cfg_cmd->completion);
 
-	ep->ep_state &= ~EP_SOFT_CLEAR_TOGGLE;
 	xhci_free_command(xhci, cfg_cmd);
 cleanup:
 	xhci_free_command(xhci, stop_cmd);
+	if (ep->ep_state & EP_SOFT_CLEAR_TOGGLE)
+		ep->ep_state &= ~EP_SOFT_CLEAR_TOGGLE;
 }
 
 static int xhci_check_streams_endpoint(struct xhci_hcd *xhci,
-- 
2.28.0