Re: [PATCH 2/2] xhci: check for a pending command completion during command timeout

[Paul Menzel]

Dear Greg,


Am 22.05.26 um 11:23 schrieb Greg Kroah-Hartman:
> On Fri, May 22, 2026 at 10:58:27AM +0200, Paul Menzel wrote:
> > From: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
> >
> > It's possible a command times out even if xHC hardware already completed
> > the command. Driver is unaware of the command completion if interrupt
> > handler is blocked for a long time.
> >
> > Check if there is an unhandled command completion on the event ring during
> > command timeout.
> >
> > In this case just give the command additional time to complete. There's no
> > point in aborting the command ring to move past a stuck command.
> >
> > Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
> > Signed-off-by: George D Sworo <george.d.sworo@xxxxxxxxx>
> > Link: https://chromium.googlesource.com/chromiumos/third_party/kernel/+/478ab723af9414b0a2a2fbc59ac34f5d319a4fc3
> > [pmenzel: one adaptation for mainline 7.1: next_trb() uses the
> >    2-argument form next_trb(&seg, &deq) — the mainline 7.1 signature
> >    dropped the xhci and ring arguments present in the 6.12 source the
> >    patch was ported from.  xhci_pending_interrupt() is used directly as
> >    it is now committed as the preceding prerequisite.]
> > Assisted-by: Claude Sonnet 4.6
> > [pmenzel: No devices with the problem available, but no regressions on
> >    Dell XPS 13 9360 and QEMU 7.2.0.
> >
> >        qemu-system-x86_64 -enable-kvm -cpu host -m 3G -device qemu-xhci,id=xhci -device usb-storage,bus=xhci.0
> >
> >    xHCI host controller initialised cleanly, USB 3.0 SuperSpeed root
> >    hubs and USB mass storage device enumerated without errors.
> >    The specific race (command timeout with blocked interrupt handler)
> >    cannot easily be forced in QEMU, but no regressions in the normal
> >    command path were observed.]
>
> What are these additions from?  Did you mean to send these out to the
> lists?

Yes, they are authored by me and meant for the list. I wanted to 
document, where I got the patch from and how I tested the change. Feel 
free to remove them.


Kind regards,

Paul