RE: [alsa-devel] [PATCH] ASoC: atmel_ssc_dai: Track playback and capture CMR dividers separately.

[Peter Rosin <peda@axentia.se>]

Hi!

> Hi Peter,
> 
> On 10/21/2014 09:05 PM, Peter Rosin wrote:
> > I did some further tests, and the following program fails without the patch:
> 
> With the patch, it is OK?

Yes.

> > #include <sys/ioctl.h>
> > #include <unistd.h>
> > #include <fcntl.h>
> > #include <sys/soundcard.h>
> >
> > int
> > main(void)
> > {
> > 	int fd;
> > 	int format;
> > 	int channels;
> >
> > 	if ((fd = open("/dev/dsp", O_WRONLY, 0)) == -1) {
> > 		perror("open");
> > 		return 1;
> > 	}
> > 	format = AFMT_S16_LE;
> > 	if (ioctl(fd, SNDCTL_DSP_SETFMT, &format) == -1) {
> > 		perror("SNDCTL_DSP_SETFMT");
> > 		return 1;
> > 	}
> > 	channels = 2;
> > 	if (ioctl(fd, SNDCTL_DSP_CHANNELS, &channels) == -1) {
> > 		perror("SNDCTL_DSP_CHANNELS");
> > 		return 1;
> > 	}
> > 	return 0;
> > }
> >
> > Output:
> > SNDCTL_DSP_CHANNELS: Device or resource busy
> 
> This return from codec or from atmel_ssc_dai?

This -EBUSY definitely comes from atmel_ssc_set_dai_sysclk, when my
card-driver tries to set ATMEL_SSC_CMR_DIV. With the patch, it works.
(the codec is spdif-transmitter, since the i2c interface of the actual tfa9879
codec is not directly reachable from the linux cpu, but that has nothing to
do with this issue).

> > (I admin to having edited the above code slightly in this mail, so I
s/admin/admit/
> > might have introduced some silly bug, but you get what I mean, just
> > open the device and request some parameters, and boom: -EBUSY)

Cheers,
Peter