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

[Dmitry Osipenko]

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.