Hi Igor,
we have checked all the signals with a digital scope.
1. SAI2_MCLK.
We can see a valid 12288000 Hz clock signal as soon as we execute "aplay piano2.wav".
See the attached picture
When the player stops the clock disappears. So far so good.
2. SAI2_BCLK, SAI2_SYNC, SAI2_TXD.
We can see problems with all these signals trying to play any sound.
All these signals are "1" initially.
As soon as we execute "aplay piano2.wav" all the lines are changed to "0".
When the player stops ( in exact 10 seconds) they change back to "1".
In other words, we can see some activity. It looks like the sound device is opened
successfully in the player ( so all pins are initialized properly). However, the audio data stream
is not applied.
The same 10-sec behavior we can see with a "speaker-test" command.
It is interesting. When we execute "arecord someFile" all these signals are getting valid.
For example, we can see 250KHz on SAI2_BCLK.
Also, we can see activities/pulses on other SAI lines. IMHO, the SAI2 works.
3.
It seems the ALSA framework stops the stream and returns the error code EIO
if there is no interrupt for ten seconds.
Probably the interrupts do not work for some reason in our system.
cat /proc/interrupts
CPU0
16: 7709 GPC 55 Level i.MX Timer Tick
19: 1412 GPC 26 Level 2020000.serial
20: 0 GPC 98 Level sai
...
Do you have any extra ideas ?
Thanks in advance
Vitaliy, Ashish
