[alsa-devel] Timer instability

[Clive Messer]

On Wednesday 25 Feb 2009 18:13:47 Takashi Iwai wrote:

> > > diff --git a/src/pcm/pcm_hw.c b/src/pcm/pcm_hw.c
> > > index e9ce092..5211d1c 100644
> > > --- a/src/pcm/pcm_hw.c
> > > +++ b/src/pcm/pcm_hw.c
> > > @@ -131,6 +131,10 @@ struct timespec snd_pcm_hw_fast_tstamp(snd_pcm_t
> > > *pcm) static int sync_ptr1(snd_pcm_hw_t *hw, unsigned int flags)
> > >  {
> > >         int err;
> > > +       long old_hwptr, new_hwptr;
> > > +       long old_applptr, new_applptr;
> > > +       old_hwptr = hw->sync_ptr->s.status.hw_ptr;
> > > +       old_applptr = hw->sync_ptr->c.control.appl_ptr;
> > >         hw->sync_ptr->flags = flags;
> > >         err = ioctl((hw)->fd, SNDRV_PCM_IOCTL_SYNC_PTR,
> > > (hw)->sync_ptr); if (err < 0) {
> > > @@ -138,6 +142,11 @@ static int sync_ptr1(snd_pcm_hw_t *hw, unsigned
> > > int flags) SYSMSG("SNDRV_PCM_IOCTL_SYNC_PTR failed");
> > >                 return err;
> > >         }
> > > +       new_hwptr = hw->sync_ptr->s.status.hw_ptr;
> > > +       new_applptr = hw->sync_ptr->c.control.appl_ptr;
> > > +       printf("sync_ptr1: %ld(%ld), %ld(%ld)\n",
> > > +              new_hwptr, new_hwptr - old_hwptr,
> > > +              new_applptr, new_applptr - old_applptr);
> > >         return 0;
> > >  }
> > >  

With sync_ptr I cannot reproduce the very large numbers. Here's a typical log. 
(Attached).

Regards

Clive
-- 
Clive Messer <clive at vacuumtube.org.uk>

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