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<b><a class="bz_bug_link
bz_status_NEW "
title="NEW - severe underruns with usb audio, works with pa 3.0 - buffer setup seems wrong"
href="https://bugs.freedesktop.org/show_bug.cgi?id=86262#c21">Comment # 21</a>
on <a class="bz_bug_link
bz_status_NEW "
title="NEW - severe underruns with usb audio, works with pa 3.0 - buffer setup seems wrong"
href="https://bugs.freedesktop.org/show_bug.cgi?id=86262">bug 86262</a>
from <span class="vcard"><a class="email" href="mailto:superquad.vortex2@gmail.com" title="Raymond <superquad.vortex2@gmail.com>"> <span class="fn">Raymond</span></a>
</span></b>
<pre>(In reply to David Mansfield from <a href="show_bug.cgi?id=86262#c2">comment #2</a>)
<span class="quote">> Created <span class=""><a href="attachment.cgi?id=109438" name="attach_109438" title="force tsched even in "BATCH" mode and on KVM.">attachment 109438</a> <a href="attachment.cgi?id=109438&action=edit" title="force tsched even in "BATCH" mode and on KVM.">[details]</a></span> <a href='page.cgi?id=splinter.html&bug=86262&attachment=109438'>[review]</a> [review]
> force tsched even in "BATCH" mode and on KVM.
>
> The attached patch fixes the problem by essentially reversing commit
> 826c8f69d34ef49e86fe0ab6c93c1ffba8916131 (alsa: Disable timer-scheduling for
> PCMs with the BATCH flag).
>
> Without tsched, the buffers are miniscule and we get overruns constantly.
> With tsched (by design) the buffers are huge.
>
> Not sure what the implications are.
>
> NOTE: I also forced enablement of tsched on KVM. I'm having the exact same
> problem in a VM, and it is MUCH better with the patch although still not
> "glitch-free" which it is (with the patch) on bare-metal.
>
> NOTE: In kvm I am using USB passthrough, not emulated hardware audio device.</span >
those emulated ac97 or hda-intel does not work with timer scheduling
so you have to post your patch in mailing list for review</pre>
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