Re: USB-Audio: Device or resource busy (strace log)
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From: Muni Sekhar <hidden>
Date: 2021-08-13 16:29:48
Also in:
alsa-devel, linux-sound, linux-usb, lkml
On Wed, Aug 11, 2021 at 6:48 PM Muni Sekhar [off-list ref] wrote:
On Wed, Aug 11, 2021 at 6:19 PM vishnu [off-list ref] wrote:quoted
can you paste output of arecord -l (list of capture devices).$ arecord -l **** List of CAPTURE Hardware Devices **** card 0: USB [Plantronics .Audio 628 USB], device 0: USB Audio [USB Audio] Subdevices: 1/1 Subdevice #0: subdevice #0quoted
Which device you are using and os. Does this instance is already open by default? like any video playing or something like that?lsof does not catch it.quoted
Yes you can stop pulse audio and try.. On Wed, Aug 11, 2021 at 6:17 PM Jaroslav Kysela [off-list ref] wrote:quoted
On 11. 08. 21 14:36, Muni Sekhar wrote:quoted
Hi All, $ cat /proc/asound/cards 0 [USB ]: USB-Audio - Plantronics .Audio 628 USB Plantronics Plantronics .Audio 628 USB at usb-0000:00:14.0-2, full speed I am using a Plantronics USB Audio headset. $ arecord --device hw:0,0 --channels 2 --format S16_LE --rate 44100Hz x.wav arecord: main:722: audio open error: Device or resource busy 'arecord' command always fails the first time after system boot in my system. But subsequent execution of the 'arecord' command runs fine. I've attached the strace log for the "audio open error: Device or resource busy" failure. Is there any fix available for this issue?You may check which other task blocks the PCM device: lsof /dev/snd/pcmC0D0cIt does not output any process. $ lsof /dev/snd/pcmC0D0c 1st run: ---------- $ arecord --device hw:0,0 --channels 2 --format S16_LE --rate 44100Hz x.wav arecord: main:722: audio open error: Device or resource busy 2nd run: ---------- $ arecord --device hw:0,0 --channels 2 --format S16_LE --rate 44100Hz x.wav Recording WAVE 'x.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo ^CAborted by signal Interrupt...quoted
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I guess that it will be pulseaudio (device enumeration).
I see that pulseaudio is getting loaded on invoking the 1st run of 'arecord' command. Here is the log: After system boot I verified that pulseaudio is not in the memory. test@test594:~$ uptime 21:39:27 up 0 min, 1 user, load average: 0.70, 0.25, 0.09 test@test594:~$ ls -ltr /dev/snd/controlC1 crw-rw---- 1 root audio 116, 2 Aug 13 21:38 /dev/snd/controlC1 test@test594:~$ ls -ltr /dev/snd/ total 0 crw-rw---- 1 root audio 116, 33 Aug 13 21:38 timer crw-rw---- 1 root audio 116, 1 Aug 13 21:38 seq crw-rw---- 1 root audio 116, 3 Aug 13 21:38 pcmC1D0p crw-rw---- 1 root audio 116, 4 Aug 13 21:38 pcmC1D0c crw-rw---- 1 root audio 116, 2 Aug 13 21:38 controlC1 drwxr-xr-x 2 root root 60 Aug 13 21:38 by-path drwxr-xr-x 2 root root 60 Aug 13 21:38 by-id test@test594:~$ lsof /dev/snd/controlC1 test@test594:~$ lsof /dev/snd/pcmC1D0c test@test594:~$ 1st run of 'arecord': ------------------------- I triggered 'arecord' after 2 mins of the system boot. In the 1st run, it failed with "Device or resource busy" and I see that pulseaudio loaded in the memory. Why does pulseaudio get triggered on running the alsa-utils command? How is the failure message "Device or resource busy" from the kernel code? test@test594:~$ arecord --device hw:1,0 --channels 2 --format S16_LE --rate 44100Hz x.wav arecord: main:722: audio open error: Device or resource busy test@test594:~$ test@test594:~$ lsof /dev/snd/pcmC1D0c COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME pulseaudi 1550 test mem CHR 116,4 463 /dev/snd/pcmC1D0c pulseaudi 1550 test 27u CHR 116,4 0t0 463 /dev/snd/pcmC1D0c test@test594:~$ lsof /dev/snd/controlC1 COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME pulseaudi 1550 test 20u CHR 116,2 0t0 461 /dev/snd/controlC1 pulseaudi 1550 test 26u CHR 116,2 0t0 461 /dev/snd/controlC1 test@test594:~$ lsof /dev/snd/pcmC1D0p test@test594:~$ test@test594:~$ uptime 21:41:06 up 2 min, 1 user, load average: 0.20, 0.19, 0.08 2nd run of 'arecord': ------------------------- The subsequent run of arecord runs fine without any issues even though pulseaudio is still in memory. test@test594:~$ arecord --device hw:1,0 --channels 2 --format S16_LE --rate 44100Hz x.wav Recording WAVE 'x.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo ^CAborted by signal Interrupt... test@test594:~$ uptime 21:41:22 up 2 min, 1 user, load average: 0.14, 0.18, 0.08 test@test594:~$ What is the role of pulseaudio? Is there a way to disable it from running it? Disabling pulseaudio causes any issues while testing audio drivers?
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Jaroslav -- Jaroslav Kysela [off-list ref] Linux Sound Maintainer; ALSA Project; Red Hat, Inc.-- Thanks, Sekhar
-- Thanks, Sekhar _______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies