Rockchip/rk3399-gru-sound: Use 48KHz sample rate for all devices

[GitHub pull_request - opened]

alsa-project/alsa-ucm-conf pull request #201 was opened from alpernebbi:

The rk3399-gru-kevin board has problems when trying to simultaneously playback and record audio with the default PulseAudio sample rate of 44.1KHz. When the following command is run, the playback starts a few seconds after the recording finishes.

    arecord -vvv -d 4 /dev/null & sleep 0.2; speaker-test -l 1 -p 100000 -t sine

When the sample rates are set to 48KHz either with PA configuration or in the UCM, playback and recording both start immediately. Another example is when a music player is running and we start `arecord`, the music starts stuttering but `arecord` can't record anything either.

Apparently, this is a hardware limitation due to the I2S lines being shared between the devices. Set all the device rates to 48KHz like Chrome OS does to make things work smoothly.

[1] https://chromium-review.googlesource.com/389695
[2] https://chromium-review.googlesource.com/898682

Request URL   : https://github.com/alsa-project/alsa-ucm-conf/pull/201
Patch URL     : https://github.com/alsa-project/alsa-ucm-conf/pull/201.patch
Repository URL: https://github.com/alsa-project/alsa-ucm-conf