Re: [PATCH] xhci: Always restore EP_SOFT_CLEAR_TOGGLE even if ep reset failed

From: Ding Hui
Date: Fri Aug 21 2020 - 19:58:37 EST


On 2020/8/21 4:44 下午, Mathias Nyman wrote:
On 21.8.2020 10.31, Greg KH wrote:
On Fri, Aug 21, 2020 at 03:06:52PM +0800, Ding Hui wrote:
Some devices driver 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

xhch_endpoint_reset failed and left ep_state's EP_SOFT_CLEAR_TOGGLE
bit is still on

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

Can't enqueue URB while manually clearing toggle

We need restore ep_state EP_SOFT_CLEAR_TOGGLE bit after
xhci_endpoint_reset, even if it is failed.

Signed-off-by: Ding Hui <dinghui@xxxxxxxxxxxxxx>

Thanks, nice catch.

---
drivers/usb/host/xhci.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

Shouldn't this have a Fixes: tag on it and be backported to the affected
stable trees?

Sorry for missing the tags, this is my first kernel patch :-)


It should, but I like this patch and want it in, so I'll add the tags this time.

Thanks for correcting my commit msg


Thanks
-Mathias



--
Thanks,
-dinghui