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

[Alex Xu (Hello71)]

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.

Thanks,
Alex.