Re: 2.6.34-rc1: regression: ^Z no longer stops sound

From: Bill Davidsen
Date: Wed Mar 24 2010 - 12:47:57 EST


Clemens Ladisch wrote:
Pavel Machek wrote:
On Sun 2010-03-14 17:20:13, Bill Davidsen wrote:
Pavel Machek wrote:
In 2.6.33, hitting ^Z stopped mpg123 in a way you'd expect (both on
thinkpad and geode notebook).

On 2.6.34-rc1, hit ^Z and sound starts looping.
That's not new, I have seen it back as far as 2.6.27.25 doing a suspend in a VM (KVM, no libvirt). But it only happens a few times a year, so I never chased it. I hate to report an occasional problem in an obsolete kernel, and I can't reproduce it.

Does it happen repeatably with the new kernel?
It happened reliably so far, yes.

This sounds as if the device has been configured to ignore underruns.
What are the contents of /proc/asound/card0/pcm0p/sub0/{sw_params,status}
when it's looping, and when it's really suspended?

If you can give me a hint how to read /proc when the machine is suspended, other than waking it up, I'll certainly check the next time I see it.

But after reading your thought on underruns, I think you right. I see from a note I wrote myself that I get this while pushing a wav file over the network to run "play" (from sox) on another machine. Every once in a while it finds a musical phrase it really likes. I had assumed it was a bug in sox, but a bug or mis-configure in the device fits all of the observed cases I've seen.

--
Bill Davidsen <davidsen@xxxxxxx>
"We can't solve today's problems by using the same thinking we
used in creating them." - Einstein

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