Using snd_soc_sst_acpi the audio device within the Dell Venue 8 Pro tablet is working fine for audio output as long a alsa state file is loaded. Audio input on the other hand is not working at all, there is only a constant noise level on the volume bar. What kind of debug logs are necessary in order to analyse this issue in case this is not already known?
We have been debugging this off-list with Jan. There are couple patches queued for byt-rt5640 based machines along the patch that adds microphone support for the Dell Venue 8 Pro tablet: https://git.kernel.org/cgit/linux/kernel/git/broonie/sound.git/commit/?h=for-next&id=24221dcc8be736a2b0b83ecaeb60b99bd7e9334c These patches most probably will be queued for Linux 3.18.
I am trying to capture sound from the internal microphone of the Dell Venue 8 Pro 5830 and I am only getting static. I am running a compiled 3.18 kernel with the referenced patch already added. I am also using an alsa state file that allows for sound playback. Are there certain alsamixer options that should be enabled? I have played with the alsamixer settings with no luck.
I have the same issue with an ASUS T100: no sound from the internal microphone! I have tried kernel 3.18 and 3.19, Fedlet and Ubuntu, without any luck. The patches of Jarkko Nikula enabled recording from an EXTERNAL microphone (connected to the mini-jack port of the tablet), at least for my device.
please try with a more recent kernel, this should be fixed.