USB-Audio: Device or resource busy (strace log)

Fri Aug 13 13:06:38 EDT 2021

You can disable pulseaudio by following below link..

https://askubuntu.com/questions/8425/how-to-temporarily-disable-pulseaudio

But need to find why its not working..

On Fri, Aug 13, 2021, 21:59 Muni Sekhar <munisekharrms at gmail.com> wrote:

> On Wed, Aug 11, 2021 at 6:48 PM Muni Sekhar <munisekharrms at gmail.com>
> wrote:
> >
> > On Wed, Aug 11, 2021 at 6:19 PM vishnu <vardhanraj4143 at gmail.com> wrote:
> > >
> > > 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 #0
> >
> >
> > > 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.
> >
> > >
> > > Yes you can stop pulse audio and try..
> > >
> > > On Wed, Aug 11, 2021 at 6:17 PM Jaroslav Kysela <perex at perex.cz>
> wrote:
> > >>
> > >> On 11. 08. 21 14:36, Muni Sekhar wrote:
> > >> > 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/pcmC0D0c
> > It 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...
> >
> >
> > >>
> > >> 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 at test594:~$ uptime
>  21:39:27 up 0 min,  1 user,  load average: 0.70, 0.25, 0.09
> test at test594:~$ ls -ltr /dev/snd/controlC1
> crw-rw---- 1 root audio 116, 2 Aug 13 21:38 /dev/snd/controlC1
> test at 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 at test594:~$ lsof /dev/snd/controlC1
> test at test594:~$ lsof /dev/snd/pcmC1D0c
> test at 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 at 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 at test594:~$
> test at 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 at 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 at test594:~$ lsof /dev/snd/pcmC1D0p
> test at test594:~$
> test at 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 at 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 at test594:~$ uptime
>  21:41:22 up 2 min,  1 user,  load average: 0.14, 0.18, 0.08
> test at 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?
>
>
> > >>
> > >>                                         Jaroslav
> > >>
> > >> --
> > >> Jaroslav Kysela <perex at perex.cz>
> > >> Linux Sound Maintainer; ALSA Project; Red Hat, Inc.
> >
> >
> >
> > --
> > Thanks,
> > Sekhar
>
>
>
> --
> Thanks,
> Sekhar
>
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