Bug 652165
| Summary: | ALSA: fix sysfs related issues (modules cannot be reloaded) and mutex problem in OSS mixer emulation | ||||||
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| Product: | Red Hat Enterprise Linux 5 | Reporter: | Jaroslav Kysela <jkysela> | ||||
| Component: | kernel | Assignee: | Jaroslav Kysela <jkysela> | ||||
| Status: | CLOSED ERRATA | QA Contact: | desktop-bugs <desktop-bugs> | ||||
| Severity: | high | Docs Contact: | |||||
| Priority: | low | ||||||
| Version: | 5.6 | CC: | cmeadors, vbenes | ||||
| Target Milestone: | rc | ||||||
| Target Release: | --- | ||||||
| Hardware: | Unspecified | ||||||
| OS: | Unspecified | ||||||
| Whiteboard: | |||||||
| Fixed In Version: | Doc Type: | Bug Fix | |||||
| Doc Text: | Story Points: | --- | |||||
| Clone Of: | Environment: | ||||||
| Last Closed: | 2011-01-13 22:00:36 UTC | Type: | --- | ||||
| Regression: | --- | Mount Type: | --- | ||||
| Documentation: | --- | CRM: | |||||
| Verified Versions: | Category: | --- | |||||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||
| Cloudforms Team: | --- | Target Upstream Version: | |||||
| Embargoed: | |||||||
| Attachments: |
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Description
Jaroslav Kysela
2010-11-11 08:27:16 UTC
Created attachment 459688 [details]
Patch for issues described above
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux maintenance release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Update release for currently deployed products. This request is not yet committed for inclusion in an Update release. in kernel-2.6.18-236.el5 You can download this test kernel (or newer) from http://people.redhat.com/jwilson/el5 Detailed testing feedback is always welcomed. Hi,
after execution of
awk '/^snd/||/^sound/&&($3==0){system("rmmod " $1)}' /proc/modules /proc/modules /proc/modules
I can see this error:
WARNING: at fs/proc/generic.c:734 remove_proc_entry()
Call Trace:
[<ffffffff8010ae33>] remove_proc_entry+0xd7/0x13e
[<ffffffff8827ebaa>] :snd:snd_info_done+0x54/0x58
[<ffffffff8827eb09>] :snd:alsa_sound_exit+0xe/0x3b
[<ffffffff800a8559>] sys_delete_module+0x196/0x1c5
[<ffffffff8005d28d>] tracesys+0xd5/0xe0
however, the device can be enabled again so it looks quite bogus. Any idea why is this error shown while removing snd_hda_intel (and other sound modules) via above mentioned command?
Is there any reproducer for testing the other bug (stalled mutex issues)?
Thanks in advance,
Vladimir
This warning is caused by removing of the 'snd.ko' (the single snd_hda_intel.ko can be removed and inserted without warning). Unfortunately, I don't see the real culprit. The backtrace shows the bug in:
if (S_ISLNK(de->mode) && de->data)
kfree(de->data);
.. but the snd_proc_root should not be marked as link (it is real directory). I hope that it's not a memory corruption. Anyway, it does not seem like a major issue - it's very rare that customers will replace all sound modules. Usually, only the front modules like snd-hda-intel are reloaded.
The stalled mutex issues can be reproduced when the OSS mixer controls are reassigned to another ALSA mixer control:
echo "MASTER \"Master Playback Volume\" 0" > /proc/asound/card0/oss_mixer
echo "MASTER \"Front Playback Volume\" 0" > /proc/asound/card0/oss_mixer
The list of available ALSA control names can be obtained using 'amixer contents'. The last parameter is control index value.
Just open/close an OSS mixer application and apply the changes to procfs simultaneously.
working fine.. created bug 664726 for the above mentioned trace -> VERIFIED An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2011-0017.html |