Trent Piepho wrote:
> I do not think the saa7134-alsa driver supports mmap.  The cx88-alsa driver
> also claimed to support mmap, but it never worked until I fixed it.  It's
> pretty clear that the code in saa7134-alsa was based on the same code as
> cx88-alsa, so it's likely it has the same bug.

You are right. The patch below (based on your cx88 patch, but I don't
really understand it) fixes mmap support in saa7134-alsa for me.
Recording via mmap (arecord -M -f S16_LE -c 2 -r 32000 -D hw:1) didn't
work at all before, works now, tested for at least 20 minutes (but,
unfortunately, with one overrun at least 0.719 ms long).
Signed-off-by: NAlexander E. Patrakov <patrakov@ums.usu.ru>
Acked-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NTrent Piepho <xyzzy@speakeasy.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>