From mboxrd@z Thu Jan  1 00:00:00 1970
From: Chemsi Mehdi <chmsmehdi@gmail.com>
Subject: Is snd_pcm_hw_constraint_mask64 really needed ?
Date: Thu, 9 Mar 2017 17:23:46 +0100
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To: Vinod Koul <vinod.koul@intel.com>, alsa-devel@alsa-project.org
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Dear ALSA expert ,


I am working with an alsa codec driver  where the driver is calling
err = snd_pcm_hw_constraint_mask64(substream->runtime,
SNDRV_PCM_HW_PARAM_FORMAT, formats);
my driver is already setting format before that so I wonder why this
function is called?
Looks like it is  needed to add audio constraints to substreams at
open/startup time, but why ?
what can be the issue if I do not call it ?

Please explain to me Takashi.

Thanks a lot in advance.