Re: [PATCH v5] ASoC: SOF: Fix deadlock when shutdown a frozen userspace

[Ricardo Ribalda <ribalda@chromium.org>]

Hi Kay

Thanks for your review

On Mon, 28 Nov 2022 at 15:41, Kai Vehmanen <kai.vehmanen@linux.intel.com> wrote:
>
> Hi,
>
> On Mon, 28 Nov 2022, Ricardo Ribalda wrote:
>
> > During kexec(), the userspace is frozen. Therefore we cannot wait for it
> > to complete.
> >
> > Avoid running snd_sof_machine_unregister during shutdown.
> [...]
> >       /*
> > -      * make sure clients and machine driver(s) are unregistered to force
> > -      * all userspace devices to be closed prior to the DSP shutdown sequence
> > +      * make sure clients are unregistered prior to the DSP shutdown
> > +      * sequence.
> >        */
> >       sof_unregister_clients(sdev);
> >
> > -     snd_sof_machine_unregister(sdev, pdata);
> > -
> >       if (sdev->fw_state == SOF_FW_BOOT_COMPLETE)
>
> this is problematic as removing that machine_unregister() call will (at
> least) bring back an issue on Intel platforms (rare problem hitting S5 on
> Chromebooks).

Do you know which devices were affected or how to trigger the issue?

I have access to the ChromeOS lab, so I can test on a big variety of devices

Thanks!


>
> Not sure how to solve this, but if that call needs to be removed
> (unsafe to call at shutdown), then we need to rework how SOF
> does the cleanup.
>
> Br, Kai



-- 
Ricardo Ribalda