Hi Peter,
On 10/22/2014 12:47 PM, Peter Rosin wrote:
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 try to reproduce it (using the code your pasted directly) on atmel sama5d3xek with wm8904 code, don't meet this error.
I also go through the OSS code, I still don't find this is related with atmel_ssc_set_dai_sysclk.
So, am I missing something or something else?
(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
Best Regards, Bo Shen