Takashi Sakamoto wrote on 10/2/18 11:01 AM:
Thank you for this report and I can regenerate this problem.
$ strace alsactl monitor ... (disconnect my sound device) poll([{fd=3, events=POLLIN|POLLERR|POLLNVAL}, {fd=4, events=POLLIN|POLLERR|POLLNVAL}, {fd=5, events=POLLIN|POLLERR|POLLNVAL}], 3, -1) = 1 ([{fd=5, revents=POLLERR|POLLNVAL}]) poll([{fd=3, events=POLLIN|POLLERR|POLLNVAL}, {fd=4, events=POLLIN|POLLERR|POLLNVAL}, {fd=5, events=POLLIN|POLLERR|POLLNVAL}], 3, -1) = 1 ([{fd=5, revents=POLLERR|POLLNVAL}]) ...
This is a bug of alsactl due to handling return code of poll(2) system call[1].
In an operation to ALSA control character devices, when handled device is disconnected, a call of poll(2) returns positive value to notify events with 'EPOLLERR | EPOLLNVAL'[2].
Soon I'll post a patch to improve this behaviour of alsactl.
Thank you a lot, this is great news!
Cheers, Thomas
I'm sorry if this is not the right place to report this issue or if the problem is already, I couldn't find anything about it.
Below is the output from alsa-info.sh:
with headphones:
http://www.alsa-project.org/db/?f=0dfc632e3adafb8bc78a182e0a225bcb13bea9fa
after unplugging:
http://www.alsa-project.org/db/?f=41dbf0735fdd7cd2416a6b4a602505715d25b44f
Please let me know if you need further info.
You did enough good. Thank you and wait for a while till I'll fix it.
[1] http://git.alsa-project.org/?p=alsa-utils.git;a=blob;f=alsactl/monitor.c;hb=... [2] https://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound.git/tree/sound/c...
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