Bug 1162

Summary:	Hangs on resume after using alsa
Product:	Power Management	Reporter:	Zak Wilson (zak)
Component:	APM	Assignee:	Stephen Rothwell (apmbugs)
Status:	REJECTED INSUFFICIENT_DATA
Severity:	high	CC:	bunk, diegocg
Priority:	P2
Hardware:	i386
OS:	Linux
Kernel Version:	2.6.0-test4	Subsystem:
Regression:	---	Bisected commit-id:

Description Zak Wilson 2003-08-28 12:44:34 UTC

Distribution: Debian/Sid
Hardware Environment: IBM Thinkpad T20 - I'm not sure what details are needed.
The problem seems to be triggered by alsa. The sound card is a Cirrus Logic CS
4614/22/24.
Software Environment: I'm not sure of the details needed here either. The
problem occurs only after trying to play sound using alsa. Alsaplayer, aplay and
arts, using alsa all trigger the problem.
Problem Description: Kernel mode processor usage goes to 100% (indicated by KDE
system monitor) after resume following attempts to use alsa to attempt to play
sound. It is possible to interact with existing windows if X is running, but
trying to display a menu, open a new window or start a new process hangs.
Logging in to a different TTY also hangs.

Steps to reproduce:

Comment 1 Zak Wilson 2003-08-28 15:57:23 UTC

To reproduce:
* This probably requires a CS46xx sound card. It might even require a Thinkpad T20.
* Compile Linux 2.6.0-test4 with APM support and with alsa as modules.
* Attempt to play a WAV file with aplay, alsaplayer or (not tested) any other
player using alsa output. The player will not produce any sound output, and will
hang. If this does not occur, you will probably not be able to reproduce the
problem.
* Suspend the system, then attempt to resume.

Comment 2 Stephen Rothwell 2003-09-09 00:23:39 UTC

Does the problem occur if the ALSA modules are removed before suspending and
then reinserted after resume?

Comment 3 Zak Wilson 2003-09-10 12:22:01 UTC

Removal of alsa modules fails. Should I try recompiling with forced module
unloading?

Comment 4 Zak Wilson 2003-10-20 15:42:36 UTC

I can no longer reproduce the problem with -test8. Unless anybody else is able
to, this bug should probably be closed.

Comment 5 john stultz 2003-11-20 19:31:29 UTC

I can still reproduce a similar issue. Using a T20 w/ alsa compiled in, audio 
stops working after an APM resume. This is w/ 2.6.0-test9-bk24, but I've seen 
the problem for quite awhile.  
 
I do not see the heavy cpu usage, or system hang noted above. The only issue 
is audio no longer working. When using the OSS driver (or 2.4) I cannot 
reproduce the problem.

Comment 6 Diego Calleja 2006-01-06 17:53:44 UTC

does it happens in recent 2.6 releases?

Comment 7 Adrian Bunk 2006-04-22 09:50:57 UTC

I'm assuming this issue is already fixed in recent 2.6 kernels.

Please reopen this bug if it's still present in kernel 2.6.16.