Re: sound skipping regression introduced in 2.6.30-rc8

[Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>]

On Thursday 11 June 2009 15:56:14 Takashi Iwai wrote:
> At Thu, 11 Jun 2009 15:32:33 +0200,
> Bartlomiej Zolnierkiewicz wrote:
> > 
> > On Thursday 11 June 2009 14:02:20 David Miller wrote:
> > > From: Takashi Iwai <tiwai@suse.de>
> > > Date: Wed, 10 Jun 2009 21:37:14 +0200
> > > 
> > > > Also, it'd be helpful if you can check whether the problem exists in
> > > > the current sound git tree (for-linus branch), too.
> > > >   git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6.git for-linus
> > > 
> > > Same behavior as 2.6.30, but debugging messages are formatted differently
> > > :-)
> > > 
> > > [ 1109.062182] PCM: Lost interrupts? (stream=0, delta=16384, intr_ptr=73728)
> > > [ 1125.126123] PCM: Lost interrupts? (stream=0, delta=16384, intr_ptr=861184)
> > > [ 1131.398094] PCM: Lost interrupts? (stream=0, delta=16384, intr_ptr=1178624)
> > > [ 1135.579406] PCM: Lost interrupts? (stream=0, delta=16384, intr_ptr=1395712)
> > > [ 1145.115367] PCM: Lost interrupts? (stream=0, delta=16384, intr_ptr=1869824)
> > > [ 1152.688670] PCM: Lost interrupts? (stream=0, delta=16384, intr_ptr=2249728)
> > 
> > [ Just another data point. ]
> > 
> > I'm experiencing similar problem with the sound in recent -next kernels.
> 
> Which driver?

snd_intel8x0

> > Though the only debug data that I'm getting with xrun_debug == 1 is:
> > 
> > XRUN: pcmC0D0p:0
> > XRUN: pcmC0D0p:0
> > XRUN: pcmC0D0p:0
> > XRUN: pcmC0D0p:0
> > XRUN: pcmC0D0p:0
> > 
> > with xrun_debug == 3:
> > XRUN: pcmC0D0p:0
> > Pid: 4718, comm: audacious Not tainted 2.6.30-next-20090611-07944-gc1b019d-dirty #21
> > Call Trace:
> 
> The semantics of xrun_debug proc file was a bit changed.  Now it's
> bit flags, and 4 corresponds to the additional jiffies check (1 is to 
> show the debug message, 2 to show stack trace).
> 
> Try to set 5 to xrun_debug.  Do you get other messages?

With xrun_debug == 5 I get:

PCM: hw_ptr skipping! (pos=14336, delta=15893, period=1024, jdelta=3/90)
PCM: hw_ptr skipping! (pos=11264, delta=15893, period=1024, jdelta=3/90)
PCM: hw_ptr skipping! (pos=7168, delta=15888, period=1024, jdelta=3/90)
PCM: hw_ptr skipping! (pos=8192, delta=15915, period=1024, jdelta=3/90)
PCM: hw_ptr skipping! (pos=15360, delta=15888, period=1024, jdelta=3/90)
XRUN: pcmC0D0p:0
PCM: hw_ptr skipping! (pos=6144, delta=15890, period=1024, jdelta=3/90)
PCM: hw_ptr skipping! (pos=3072, delta=15890, period=1024, jdelta=3/90)

[ They seem to be the same as reported by davem against 2.6.30. ]

and the skipping is gone.