Re: [PATCH 1/3] ALSA: hda/tegra: Skip reset on BPMP devices

[Sameer Pujar]

On 12/7/2021 5:35 PM, Dmitry Osipenko wrote:
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> 07.12.2021 15:00, Sameer Pujar пишет:
> > On 12/7/2021 3:52 PM, Dmitry Osipenko wrote:
> > > 07.12.2021 09:32, Sameer Pujar пишет:
> > > > HDA regression is recently reported on Tegra194 based platforms.
> > > > This happens because "hda2codec_2x" reset does not really exist
> > > > in Tegra194 and it causes probe failure. All the HDA based audio
> > > > tests fail at the moment. This underlying issue is exposed by
> > > > commit c045ceb5a145 ("reset: tegra-bpmp: Handle errors in BPMP
> > > > response") which now checks return code of BPMP command response.
> > > >
> > > > The failure can be fixed by avoiding above reset in the driver,
> > > > but the explicit reset is not necessary for Tegra devices which
> > > > depend on BPMP. On such devices, BPMP ensures reset application
> > > > during unpowergate calls. Hence skip reset on these devices
> > > > which is applicable for Tegra186 and later.
> > > The power domain is shared with the display, AFAICS. The point of reset
> > > is to bring h/w into predictable state. It doesn't make sense to me to
> > > skip the reset.
> > Yes the power-domain is shared with display. As mentioned above,
> > explicit reset in driver is not really necessary since BPMP is already
> > doing it during unpowergate stage. So the h/w is already ensured to be
> > in a good state.
> If you'll reload the driver module, then h/w won't be reset.

How the reload case would be different? Can you please specify more 
details if you are referring to a particular scenario?