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

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Date:   Wed, 8 Dec 2021 15:05:54 +0300
From:   Dmitry Osipenko <digetx@...il.com>
To:     Sameer Pujar <spujar@...dia.com>, tiwai@...e.com,
        broonie@...nel.org, lgirdwood@...il.com, thierry.reding@...il.com,
        perex@...ex.cz
Cc:     jonathanh@...dia.com, alsa-devel@...a-project.org,
        devicetree@...r.kernel.org, linux-tegra@...r.kernel.org,
        linux-kernel@...r.kernel.org, stable@...r.kernel.org,
        Mohan Kumar <mkumard@...dia.com>, robh+dt@...nel.org
Subject: Re: [PATCH 1/3] ALSA: hda/tegra: Skip reset on BPMP devices

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.

Please make v2 using devm_reset_control_bulk_get_exclusive(), skipping
the non-existent reset, or move the workaround to the BPMP driver like I
suggested in the other reply.