[alsa-devel] [PATCH] ALSA: HDA: Lessen CPU usage when waiting for chip to respond

[Arun Raghavan]

On Wed, 2012-05-09 at 12:51 +0200, Takashi Iwai wrote:
> At Wed, 09 May 2012 01:35:52 +0530,
> Arun Raghavan wrote:
> > 
> > On Fri, 2012-05-04 at 11:05 +0200, David Henningsson wrote:
> > > When an IRQ for some reason gets lost, we wait up to a second using
> > > udelay, which is CPU intensive. This patch improves the situation by
> > > waiting about 30 ms in the CPU intensive mode, then stepping down to
> > > using msleep(2) instead. In essence, we trade some granularity in
> > > exchange for less CPU consumption when the waiting time is a bit longer.
> > > 
> > > As a result, PulseAudio should no longer be killed by the kernel
> > > for taking up to much RT-prio CPU time. At least not for *this* reason.
> > > 
> > > Signed-off-by: David Henningsson <david.henningsson at canonical.com>
> > > ---
> > >  sound/pci/hda/hda_intel.c |    6 ++++--
> > >  1 file changed, 4 insertions(+), 2 deletions(-)
> > > 
> > > Hi Arun,
> > > 
> > > Can you check if this patch resolves your problem with PulseAudio getting
> > > killed by the kernel? If so, we should apply it to the kernel, perhaps even
> > > to stable.
> > > 
> > > // David
> > 
> > Thanks, this fixes the problem for me. Don't know what the official
> > procedure for these things is, but fwiw:
> > 
> > Signed-off-by: Arun Raghavan <arun.raghavan at collabora.co.uk>
> 
> I guess you meant tested-by tag?
> In anyway I took the patch now with Cc to stable.  It'll be included
> in the next pull request to Linus.

I did, and now I know what tag to use the next time. :)

Thanks,
Arun