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

From: Sameer Pujar
Date: Tue Dec 14 2021 - 01:02:52 EST




On 12/8/2021 5:35 PM, Dmitry Osipenko wrote:
08.12.2021 08:22, Sameer Pujar пишет:

On 12/7/2021 11:32 PM, Dmitry Osipenko wrote
If display is already active, then shared power domain is already
ungated.
If display is already active, then shared power domain is already
ungated. HDA reset is already applied during this ungate. In other
words, HDA would be reset as well when display ungates power-domain.
Now, if you'll reload the HDA driver module while display is active,
you'll get a different reset behaviour. HDA hardware will be reset on
pre-T186, on T186+ it won't be reset.

How the reset behavior is different? At this point when HDA driver is loaded the HW is already reset during display ungate. What matters, during HDA driver load, is whether the HW is in predictable state or not and the answer is yes. So I am not sure what problem you are referring to. Question is, if BPMP already ensures this, then why driver needs to take care of it.