On Mon, 8 Nov 2010, pl bossart wrote:
I feel that some bottom-line check is needed if we keep the linear
position over the buffer size even without the period irq.
If the app doesn't care, OK fine, the driver shouldn't care, too.
But then it doesn't make sense to keep the linear position, either.
But if we can keep the linear position using the light-weight jiffies
check, it's probably OK to keep it rather than changing the hw_ptr
behaviour.
Well, but the point of the patch is to avoid wakeups as much as
possible. ÂThe jiffies-check adds an unconditional wakeup for each
buffer size, thus it's against the purpose of the patch.
I don't see any wakeup.
The CPU is woken up. ÂThis is to be avoided.
Nope. No timers are used. The jiffies check and hw_ptr correction should be
done from the avail_update call invoked from an application.
ok, so I re-implemented all the points found in the reviews except for
this thread. There's already some code to see if we go beyond the
buffer boundaries, so I am not sure what the 'linear position' means.
Linear means that new hw_ptr must be always behind the previous hw_ptr.
Jaroslav
-----
Jaroslav Kysela <perex@xxxxxxxx>
Linux Kernel Sound Maintainer
ALSA Project, Red Hat, Inc.
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