Bug 101431

Summary:	snd_usb_line6 device busy when monitor channel is activated
Product:	Drivers	Reporter:	Michael Lhomme (papylhomme)
Component:	Sound(ALSA)	Assignee:	Jaroslav Kysela (perex)
Status:	NEW ---
Severity:	normal	CC:	tiwai
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	4.0.7	Subsystem:
Regression:	No	Bisected commit-id:
Attachments:	Test fix patch Test fix patch #2

Description Michael Lhomme 2015-07-13 09:22:17 UTC

Hello,

I had been unable to use my POD Studio UX1 for some time, the device appearing busy as soon as I plugged it. *aplay* reported "device or resource busy" even without DE or daemon running, and *lsof* didn't report any processes holding a lock on the device.

Eventually I tried to fidget the settings in alsamixer out of curiosity, and it appears that the monitor channel is somehow responsible for the lock: if I turn it off (value to 0), the device is available and working.

Comment 1 Takashi Iwai 2015-07-13 10:01:50 UTC

Looks like the monitor PCM concurrent check is wrong.  Could you try the patch below?

Comment 2 Takashi Iwai 2015-07-13 10:02:10 UTC

Created attachment 182501 [details]
Test fix patch

Comment 3 Michael Lhomme 2015-07-13 12:17:55 UTC

It doesn't work. Additionaly there is an unusual behaviour with the monitor channel now, if I try to increase or decrease the value, it jump directly to 0, and then I'm unable to change it.

Comment 4 Takashi Iwai 2015-07-13 12:40:29 UTC

OK, then how about another one?

Comment 5 Takashi Iwai 2015-07-13 12:40:44 UTC

Created attachment 182521 [details]
Test fix patch #2

Comment 6 Michael Lhomme 2015-07-13 14:05:39 UTC

Well, definitely better :-) No more lock on the resource, and the monitor channel is working as expected.

Thanks for you really prompt support !