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Subject: Re: [PATCH 2/2] ASoC: Intel: Add period size constraint on strago
 board
From:   Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
To:     "Lu, Brent" <brent.lu@intel.com>,
        "alsa-devel@alsa-project.org" <alsa-devel@alsa-project.org>
Cc:     Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>,
        "Rojewski, Cezary" <cezary.rojewski@intel.com>,
        Kai Vehmanen <kai.vehmanen@linux.intel.com>,
        Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>,
        Jie Yang <yang.jie@linux.intel.com>,
        Takashi Iwai <tiwai@suse.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Liam Girdwood <liam.r.girdwood@linux.intel.com>,
        Sam McNally <sammc@chromium.org>,
        Mark Brown <broonie@kernel.org>,
        Ranjani Sridharan <ranjani.sridharan@linux.intel.com>,
        Daniel Stuart <daniel.stuart14@gmail.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Yu-Hsuan Hsu <yuhsuan@chromium.org>,
        Damian van Soelen <dj.vsoelen@gmail.com>
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Date:   Thu, 30 Jul 2020 10:44:47 -0500
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On 7/30/20 10:27 AM, Pierre-Louis Bossart wrote:
> 
> 
>>> Is this patch required if you've already constrained the period sizes 
>>> for the
>>> platform driver in patch1?
>>
>> Yes or alsa will select 320 as default period size for it.
> 
> ok, then that's a miss in your patch1. 320 samples is a multiple of 1ms 

typo: is NOT

> for 48kHz rates. I think it was valid only for the 16kHz VoIP paths used 
> in some versions of Android, but that we don't support in the upstream 
> code.
> 
> To build on Takashi's answer, the real ask here is to require that the 
> period be a multiple of 1ms, because that's the fundamental 
> design/limitation of firmware. It doesn't matter if it's 48, 96, 192, 
> 240, 480, 960 samples.