Public bug reported:
Hi!
I've encountered a problem with alsa system (IMO, userspace only). I've
gathered lots of debug information (I'll try to attach a tarball) and found a
temporary workaround. However, we shouldn't rely on workaround, but track down
to the source of the bug and fix it :)
Sometimes the system runs into a state, where no programs can output sound and
most of them hangs trying to produce the sound. Reboot, of course, helps, but
today I've closed all the application which uses sound (checked with lsof
/dev/snd/*) and run a small debug session. I've wrote a simple run_alsa_test
script (selfexplanatory, included under tests directory in a tarball) and have
run it several times under different conditions. The script, among other
things, produces strace output and core dump of aplay command (aplay doesn't
crash, it just hangs trying to operate on some semaphore). Do grep for values
5678293 and 24379393 on all submitted files -- these values are not random.
Looking at strace output gave me a hint to change defaults.pcm.ipc_key value at
~/.asoundrc.asoundconf. After this the sound returned and all seems to work
fine. Should we look closer at dmix plugin? What it does with IPC resources on
normal exit and when killed?
The output of `ltrace -S -f -n 2 -s 4096 aplay
/usr/share/sounds/pop.wav` is also included and shows that the
application hangs on snd_pcm_open library call.
I'm using Kubuntu Feisty on amd64 platform, GA-M57SLI-S4 motherboard,
NVIDIA nForce 570 SLI chipset with onboard sound, see uname, lsb-
release, dpkg-l, dmesg, lspci*, lsmod, etc. in a tarball. In addition I
include the whole /proc/asound directory for your convenience. All other
files mentioned above are included too. Hope, this information is enough
to find the root of the bug :)
Regards,
Ilia.
** Affects: alsa-lib (Ubuntu)
Importance: Undecided
Status: Unconfirmed
--
sometimes no sound could be played and aplay stucks at semop() syscall
https://bugs.launchpad.net/bugs/115593
You received this bug notification because you are a member of Ubuntu
Bugs, which is the bug contact for Ubuntu.
--
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
