[PATCH] usb: xhci: reset endpoint on USB stall

[Bin Meng]

Hi Stefan,

On Wed, Jan 5, 2022 at 3:48 AM Stefan Agner <stefan at agner.ch> wrote:
>
> Bin Meng,
>
> On 2021-09-27 17:14, Marek Vasut wrote:
> > On 9/27/21 2:42 PM, Stefan Agner wrote:
> >> There are devices which cause a USB stall when trying to read strings.
> >> Specifically Arduino Mega R3 stalls when trying to read the product
> >> string.
> >>
> >> The stall currently remains unhandled, and subsequent retries submit new
> >> transfers on a stopped endpoint which ultimately cause a crash in
> >> abort_td():
> >> WARN halted endpoint, queueing URB anyway.
> >> XHCI control transfer timed out, aborting...
> >> Unexpected XHCI event TRB, skipping... (3affe040 00000000 13000000 02008401)
> >> BUG at drivers/usb/host/xhci-ring.c:505/abort_td()!
> >> BUG!
> >> resetting ...
> >>
> >> Linux seems to be able to recover from the stall by issuing a
> >> TRB_RESET_EP command.
> >>
> >> Introduce reset_ep() which issues a TRB_RESET_EP followed by setting the
> >> transfer ring dequeue pointer via TRB_SET_DEQ. This allows to properly
> >> recover from a USB stall error and continue communicating with the USB
> >> device.
> >>
> >> Signed-off-by: Stefan Agner <stefan at agner.ch>
> >
> > I hope to get AB/RB from Bin here, then it can go into this release I think.
>
> Any chance you could have a look at this to get it into this release :)
>

Sorry I missed this. I suspect it's too late for 2022.01 to include
such big changes :(

Regards,
Bin