Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [alsa-devel] [PATCH] ASoC: soc-pcm: Use delay set in pointer
 function
To:     Mark Brown <broonie@kernel.org>, Takashi Iwai <tiwai@suse.de>
Cc:     Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>,
        "moderated list:SOUND - SOC LAYER / DYNAMIC AUDIO POWER MANAGEM..." 
        <alsa-devel@alsa-project.org>, Alexander.Deucher@amd.com,
        djkurtz@chromium.org, Liam Girdwood <lgirdwood@gmail.com>,
        open list <linux-kernel@vger.kernel.org>
References: <1532686422-1790-1-git-send-email-akshu.agrawal@amd.com>
 <66c8b8c4-bdd0-0129-5e5b-850890cfdb8d@linux.intel.com>
 <e0990b62-897c-6dc7-8ac9-296932c505b7@amd.com>
 <dd4d3dc6-88f3-d53f-cd5c-5035c80be3da@linux.intel.com>
 <s5hy3dsviwq.wl-tiwai@suse.de> <20180730155030.GP5789@sirena.org.uk>
From:   "Agrawal, Akshu" <Akshu.Agrawal@amd.com>
Message-ID: <7a88c7b4-d31d-b044-bb8e-a866d49d1256@amd.com>
Date:   Tue, 31 Jul 2018 06:55:06 +0530
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101
 Thunderbird/52.9.1
MIME-Version: 1.0
In-Reply-To: <20180730155030.GP5789@sirena.org.uk>
Content-Type: text/plain; charset=windows-1252
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Received-SPF: None (protection.outlook.com: amd.com does not designate
 permitted sender hosts)
SpamDiagnosticOutput: 1:99
SpamDiagnosticMetadata: NSPM
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 31 Jul 2018 01:25:28.4454 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: 6b9968e1-2e88-44c3-b54f-08d5f68481d9
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d
X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN1PR12MB2368
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org


On 7/30/2018 9:20 PM, Mark Brown wrote:
> On Mon, Jul 30, 2018 at 05:32:21PM +0200, Takashi Iwai wrote:
> 
>> That said, if delay callback of CPU dai provides the additional delay,
>> the patch does correct thing.  OTOH, if CPU dai provides the base
>> delay instead, we need to clarify that it's rather a must; the delay
>> calculation in pointer callback becomes bogus in this scenario.
> 
> Part of the theory here is that every component might have a delay
> independently of the rest and we need to add them all together to figure
> out what the system as a whole will see.  Personally I'd rather just
> have everything use a callack consistently to avoid confusion.
> 

For consistency we can add a delay callback in snd_pcm_ops and modify
the drivers which directly assigning runtime->delay to use the callback.
Apart from the 2 drivers mentioned in commit message I also found
sound/usb to be doing the same and its delay getting lost.

Thanks,
Akshu