[alsa-devel] safe support for rewind in ALSA

[Jaroslav Kysela]

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

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