[alsa-devel] BockW 4th sound doesn't work on latest linus/master

[Simon Horman]

On Mon, Jan 27, 2014 at 11:51:37PM -0800, Kuninori Morimoto wrote:
> 
> Hi Simon, Mark again
> 
> > I noticed that bockw 4th sound device doesn't work on
> > latest linus/master.
> > 
> > My git bisect said the trigger is this patch
> > 
> > e14ee5deab24200e4b70fe31a8c806f0acd3d37c
> > (ARM: shmobile: bockw: Do not enable CONFIG_DEVTMPFS defconfig)
> > 
> > This patch removed below from defconfig
> > 
> > -CONFIG_DEVTMPFS=y
> > -CONFIG_DEVTMPFS_MOUNT=y
> > 
> > But, why this has relationship to sound ??
> > 
> > #0 - #3 sound device have no problem.
> > But #4 sound device will be broken by this patch
> > Do you have any idea ?
> > 
> > --- my kernel log -------
> > ...
> > ALSA device list:
> >   #0: SSI56-AK4643
> >   #1: SSI3-AK4554(playback)
> >   #2: SSI4-AK4554(capture)
> >   #3: SSI7-AK4554(playback)
> >   #4: SSI8-AK4554(capture)
> > 
> > --- test result of 4th device (bad case) ---
> > 
> > # /home/arecord -c 2 -t wav -d 10 -r 48000 -f S16_LE -D hw:4 /tmp/hoge
> > ALSA lib pcm_hw.c:1433:(_snd_pcm_hw_open) Invalid value for card
> > arecord: main:608: audio open error: No such file or directory
> > 
> > --- test result of 4th device (good case) ---
> > 
> > # /home/arecord -c 2 -t wav -d 10 -r 48000 -f S16_LE -D hw:4 /tmp/hoge
> > Recording WAVE '/tmp/hoge' : Signed 16 bit Little Endian, Rate 48000 Hz, Stereo
> 
> My rootfs with no DEVTMPFS didn't have /dev/snd/controlC4, /dev/snd/pcmC4D0c
> It start works if I created these node.

Makes sense.

Could you post a patch to revert the offending defconfig change.

Geert tells me that DEVTMPFS is needed for udev on Debian Jesse
and is also common in other arm defconfigs. So I think it should be
enabled.