linux-kernel - Re: [PATCH 19/19] ASoC: amd: ps: increase runtime suspend delay

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Message-ID: <b61474ce-01a9-7602-e3c0-df8fdc5191c6@amd.com>
Date:   Tue, 17 Jan 2023 17:03:07 +0530
From:   "Mukunda,Vijendar" <vijendar.mukunda@....com>
To:     Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>,
        Mark Brown <broonie@...nel.org>
Cc:     "Limonciello, Mario" <mario.limonciello@....com>, vkoul@...nel.org,
        alsa-devel@...a-project.org, Mastan.Katragadda@....com,
        Sunil-kumar.Dommati@....com, Basavaraj.Hiregoudar@....com,
        Takashi Iwai <tiwai@...e.com>,
        Liam Girdwood <lgirdwood@...il.com>,
        open list <linux-kernel@...r.kernel.org>,
        Syed Saba Kareem <Syed.SabaKareem@....com>,
        arungopal.kondaveeti@....com
Subject: Re: [PATCH 19/19] ASoC: amd: ps: increase runtime suspend delay

On 16/01/23 20:32, Pierre-Louis Bossart wrote:
>
> On 1/16/23 02:35, Mukunda,Vijendar wrote:
>> On 14/01/23 01:27, Mark Brown wrote:
>>> On Fri, Jan 13, 2023 at 11:33:09AM -0600, Pierre-Louis Bossart wrote:
>>>
>>>> I do recall some issues with the codec jacks, where if the card
>>>> registration happens too late the codec might have suspended. But we
>>>> added pm_runtime_resume_and_get in the set_jack_detect callbacks, so
>>>> that was solved.
>>> Right, I would expect that whatever needs the device to be powered on
>>> would be explicitly ensuring that this is done rather than tweaking
>>> timeouts - the timeouts should be more of a performance thing to avoid
>>> bouncing power too much, not a correctness thing.
>> Machine driver probe is executed in parallel with Manager driver
>> probe sequence. Because of it, before completion of all peripherals
>> enumeration across the multiple links, if card registration is
>> completed, codec register writes will fail as Codec device numbers
>> are not assigned.
>>
>> If we understood correctly, as per your suggestion, We shouldn't use any
>> time bounds in machine driver probe sequence and before registering the
>> sound card, need to traverses through all peripheral initialization completion
>> status for all the managers.
> What's not clear in your reply is this:
>
> What codec registers are accessed as a result of the machine driver
> probe and card registration, and in what part of the card registration?
>
> Are we talking about SoundWire 'standard' registers for device/port
> management, about vendor specific ones that are exposed to userspace, or
> vendor-specific ones entirely configured by the driver/regmap.
>
> You've got to give us more data or understanding of the sequence to
> help. Saying there's a race condition doesn't really help if there's
> nothing that explains what codec registers are accessed and when.
We have come across a race condition, where sound card registration
is successful before codec enumerations across all the links gets completed
and our manager instance going into bad state.

Please refer below link for error logs.
https://pastebin.com/ZYEN928S