Subject: Re: [PATCH 1/3] ALSA: hda/tegra: Skip reset on BPMP devices
To:     Dmitry Osipenko <digetx@gmail.com>, tiwai@suse.com,
        broonie@kernel.org, lgirdwood@gmail.com, thierry.reding@gmail.com,
        perex@perex.cz
Cc:     jonathanh@nvidia.com, alsa-devel@alsa-project.org,
        devicetree@vger.kernel.org, linux-tegra@vger.kernel.org,
        linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        Mohan Kumar <mkumard@nvidia.com>, robh+dt@kernel.org
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From:   Sameer Pujar <spujar@nvidia.com>
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Date:   Tue, 7 Dec 2021 23:07:51 +0530
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On 12/7/2021 9:05 PM, Dmitry Osipenko wrote:
> External email: Use caution opening links or attachments
>
>
> 07.12.2021 17:49, Sameer Pujar пишет:
> ...
>>>> How the reload case would be different? Can you please specify more
>>>> details if you are referring to a particular scenario?
>>> You have a shared power domain. Since power domain can be turned off
>>> only when nobody keeps domain turned on, you now making reset of HDA
>>> controller dependent on the state of display driver.
>> I don't think that the state of display driver would affect. The HDA
>> driver itself can issue unpowergate calls which in turn ensures h/w
>> reset. If display driver is already runtime active, HDA driver runtime
>> resume after this would be still fine since h/w reset is already applied
>> during display runtime resume. Note that both HDA and display resets are
>> connected to this power-domain and BPMP applies these resets during
>> unpowergate.
> HDA won't be reset while display is active on T186+.

No. HDA reset is applied whenever power-domain is ungated. It can happen 
when either HDA or display device becomes active. So I don't think that 
it is inconsistent.