On Sun, 14 Jun 2020 14:07:48 +0200,
Alex Xu (Hello71) wrote:
>
> Excerpts from Takashi Iwai's message of June 14, 2020 5:54 am:
> > On Sat, 13 Jun 2020 18:25:22 +0200,
> > Alex Xu (Hello71) wrote:
> >>
> >> Excerpts from Takashi Iwai's message of June 11, 2020 1:11 pm:
> >> > Thanks, so something still missing in the mmap handling, I guess.
> >> >
> >> > I've worked on two different branches for potential fixes of your
> >> > problems. Could you test topic/dma-fix and topic/dma-fix2 branches?
> >> > git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound.git
> >> > Just pull one of them onto Linus' git HEAD.
> >> >
> >> > I guess we'll go with David's new patch, but still it's interesting
> >> > whether my changes do anything good actually.
> >> >
> >> >
> >> > Takashi
> >> >
> >>
> >> On torvalds 623f6dc593, topic/dma-fix causes sound to be output as
> >> alternating half-second bursts of noise and a few seconds of silence.
> >> topic/dma-fix2 appears to work properly.
> >
> > OK, thanks for the feedback! Just to make sure, you're using
> > PulseAudio, right?
> > If so, it was still something wrong about mmap, and the secondary
> > method (the fallback to the continuous page) looks like a safer
> > approach in the end.
> >
> > I suppose that David's fix will be merged sooner or later. Meanwhile
> > I'll work on the change in the sound driver side to make things a bit
> > more robust. They don't conflict and both good applicable.
> >
> >
> > thanks,
> >
> > Takashi
> >
>
> Ah, no, I think that wasn't clear. I use ALSA directly with mostly
> default configuration, except an asym sets separate default playback and
> record devices.
>
> asound.conf:
>
> defaults.pcm.card 1
> defaults.ctl.card 1
>
> pcm.!default {
> type asym
> playback.pcm
> {
> type plug
> slave.pcm "dmix"
> }
> capture.pcm
> {
> type plug
> slave.pcm {
> type dsnoop
> ipc_key 6793
> slave.pcm "hw:U0x46d0x81d"
> }
> }
> }
>
> I think I wasn't able to set defaults.pcm.dmix.card and
> defaults.pcm.dsnoop.card for some reason, not sure why. I can try that,
> but I don't think it will affect this mmap issue.
The dmix is an implementation exclusively with mmap, so yes, it's
still about the mmap. This also shows the same problem.
thanks,
Takashi
