[alsa-devel] safe support for rewind in ALSA

Jaroslav Kysela perex at perex.cz
Thu Feb 11 08:27:25 CET 2010

On Thu, 11 Feb 2010, Clemens Ladisch wrote:

>> Do you mean that PA only wake up once when configure sound card to use two
>> periods per buffer ?
> When using two periods per buffer, ALSA tries to wake up PA two times.
> However, PA ignores the sound card's interrupts and is woken up by its
> own timer.

PA can drive the wake-ups using avail_min sw parameter. If this value is 
high enough, no userspace wake up is called, only interrupt is processed 
and internal ring buffer pointers in the driver are updated.


Jaroslav Kysela <perex at perex.cz>
Linux Kernel Sound Maintainer
ALSA Project, Red Hat, Inc.

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