From mboxrd@z Thu Jan  1 00:00:00 1970
From: Clemens Ladisch <clemens@ladisch.de>
Subject: Re: SNDRV_PCM_INFO_BATCH
Date: Tue, 04 Mar 2014 15:50:04 +0100
Message-ID: <5315E81C.2010704@ladisch.de>
References: <5315E118.7060809@canonical.com>
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To: David Henningsson <david.henningsson@canonical.com>, "alsa-devel@alsa-project.org" <alsa-devel@alsa-project.org>
Cc: Takashi Iwai <tiwai@suse.de>, Lars-Peter Clausen <lars@metafoo.de>, General PulseAudio Discussion <pulseaudio-discuss@lists.freedesktop.org>
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David Henningsson wrote:
> So, PulseAudio removed timer scheduling for drivers with
> SNDRV_PCM_INFO_BATCH, and released 5.0. Meanwhile, USB drivers still
> have SNDRV_PCM_INFO_BATCH, so this leads to performance regressions for
> USB sound cards.
>
> The question remains - what does SNDRV_PCM_INFO_BATCH really mean?

For your purposes, it means that the pointer accuracy is likely to be
worse than that of other sound cards.

There should be a mechanism to report the actual granularity.


Regards,
Clemens