[pulseaudio-tickets] [Bug 84585] Issue of CPU usage with HiFiBerry driver snd_soc_hifiberry_amp with Debian Wheezy kernel 3.12.28

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=84585

--- Comment #23 from Raymond <superquad.vortex2 at gmail.com> ---
http://0pointer.de/blog/projects/pulse-glitch-free.html

image 1 is correct only if sound card can report dma residue, which provide
more accurate position than period boundary

if sound card cannot report dma residue, hwptr just increment by period
size/time,  your cannot rewind when using two periods per buffer


http://cgit.freedesktop.org/pulseaudio/pulseaudio/commit/src/modules/alsa/alsa-util.c?id=826c8f69d34ef49e86fe0ab6c93c1ffba8916131

https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/?id=ab69a4904b5dd4d7cd6996587ba066bca8d13838



 timer scheduling is enabled by default since pulseaudio assume all sound card
can report dma residue

-- 
You are receiving this mail because:
You are the QA Contact for the bug.
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/pulseaudio-bugs/attachments/20141008/0d6d415c/attachment.html>