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Subject: Re: [PATCH AUTOSEL 4.18 043/131] ASoC: soc-pcm: Use delay set in
 component pointer function
To:     Sasha Levin <Alexander.Levin@microsoft.com>,
        Mark Brown <broonie@kernel.org>
Cc:     "stable@vger.kernel.org" <stable@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
References: <20180902064601.183036-1-alexander.levin@microsoft.com>
 <20180902064601.183036-43-alexander.levin@microsoft.com>
 <20180903111626.GC10302@sirena.org.uk> <20180907002313.GB16300@sasha-vm>
From:   "Agrawal, Akshu" <Akshu.Agrawal@amd.com>
Message-ID: <056779f2-8b3b-63b5-ce0b-f314317156f7@amd.com>
Date:   Fri, 7 Sep 2018 12:46:21 +0530
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On 9/7/2018 5:53 AM, Sasha Levin wrote:
> On Mon, Sep 03, 2018 at 12:16:26PM +0100, Mark Brown wrote:
>> On Sun, Sep 02, 2018 at 01:03:55PM +0000, Sasha Levin wrote:
>>> From: Akshu Agrawal <akshu.agrawal@amd.com>
>>>
>>> [ Upstream commit 9fb4c2bf130b922c77c16a8368732699799c40de ]
>>>
>>> Take into account the base delay set in pointer callback.
>>>
>>> There are cases where a pointer function populates
>>> runtime->delay, such as:
>>> ./sound/pci/hda/hda_controller.c
>>> ./sound/soc/intel/atom/sst-mfld-platform-pcm.c
>>
>> I'm worried that if anyone notices this at all they will have already
>> compensated for the delays in userspace and therefore this will cause
>> them to see problems as they get double compenstation for delays.
> 
> But what happens when they update to a newer Stable? They're going to
> hit that issue anyways.
> 

Drivers which had exposed this delay in pointer function but have
compensated for the issue in userspace are likely see the problem of
double delay when the update happens.
I Don't know what is the best way to communicate that issue is fixed in
kernel and usersapce compensation isn't required.

But more likely I think the delay was just getting left out and there
wouldn't have been a compensation in userspace.

Thanks,
Akshu