On Thu, 11.02.10 08:27, Jaroslav Kysela (perex@xxxxxxxx) wrote: > > 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. We actually do set min_avail and update it depending on the latency requirements of the connected clients. Not that we set it to a value that is not necessarily a multiple of the period size. That said our primary way to wakeup is and stays the system timer, not the sound card clock. We set min_avail only as a safety net. Lennart -- Lennart Poettering Red Hat, Inc. lennart [at] poettering [dot] net http://0pointer.net/lennart/ GnuPG 0x1A015CC4 _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
