[alsa-devel] ALSA : Can't open capture device
a.bouin at kerlink.fr
Fri Jan 11 14:26:42 CET 2008
arecord answer me this :
**** List of PLAYBACK Hardware Devices ****
card 0: codec [xxxxxxx audio codec], device 0: xxxxxx xxxxxx-I2S-0 
Subdevice #0: subdevice #0
After looking for traces in pcm.c and sound.c, I've found this :
soc_new_pcm playback 1, capture 1
snd_pcm_dev_register str pcmC0D0p
snd_register_device_for_dev minor 16
snd_pcm_dev_register str pcmC0D0c
snd_register_device_for_dev minor 24
snd_register_device_for_dev minor 0
My pcmC0D0x minor devices were wrong :'( i've remade them and now it works.
Thanks a lot.
De : Clemens Ladisch [mailto:cladisch at fastmail.net]
Envoyé : vendredi 11 janvier 2008 14:17
À : Alexandre BOUIN; alsa-devel at alsa-project.org
Objet : Re: [alsa-devel] ALSA : Can't open capture device
Alexandre BOUIN wrote:
> I'm working on an intern project, using an AT91SAM9260EK-based board,
> embedded system.
> Our kernel contains a full ALSA 1.14 with ASoC layer.
> Our ASoC driver works well in capture and playback, if we are using OSS
> layer or directly /dev/dsp.
> So I need some tips on ALSA layer side :
> here you can see that my device is created :
> ll /dev/snd/
> crwxrwxrwx 1 root root 116, 0 Dec 26 2007 controlC0
> crwxrwxrwx 1 root root 116, 4 Dec 26 2007 hwC0D0
> crwxrwxrwx 1 root root 116, 14 Dec 26 2007 pcmC0D0c
> crwxrwxrwx 1 root root 116, 16 Dec 26 2007 pcmC0D0p
> ll /dev/dsp
> crwxrwxrwx 1 root root 14, 3 Dec 26 2007 /dev/dsp
> A cat on playback device works (I added some traces in kernel) :
> cat < /dev/snd/pcmC0D0p
> snd_pcm_open : enter
> snd_pcm_open_file : before snd_pcm_open_substream
> snd_pcm_open_file : after snd_pcm_open_substream
> cat: read error: Invalid argument
> But a cat on capture device does not work :
> cat < /dev/snd/pcmC0D0c
> -sh: cannot open /dev/snd/pcmC0D0c: No such device
Does the capture device appear in /proc/asound/devices or in the output
of "arecord -l"?
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