Re: next-0519 on thinkpad x60: sound related? window manager crash

Alex Xu (Hello71)
2020-06-14T12:08:59Z

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.

Thanks,
Alex.