Kernel Bug Tracker – Bug 64741
[pandaboard] audio codec only provides 96kHz output
Last modified: 2013-11-14 15:10:45 UTC
I tried the audio codec on the Pandaboard ES with 3.12 vanilla and noticed that it behaves weirs. E.g. it only provides 96kHz output.
Also mpv fails to open the device in hw mode. It only works with plughw.
According to the information from the OMAPpedia (http://www.omappedia.com/wiki/Audio_Drive_Arch), the codec should at least support 44.1kHz and 48kHz sampling rates.
Created attachment 114151 [details]
alsa-info script output
Since I already have this attached to other bugs, just the link (to the kernel config):
This is when mpv is playing back some music.
liquid@fragile /proc/asound/PandaBoardES/pcm0p/sub0 $ cat hw_params
rate: 96000 (96000/1)
liquid@fragile /proc/asound/PandaBoardES/pcm0p/sub0 $ cat info
id: TWL6040 twl6040-legacy-0
subname: subdevice #0
liquid@fragile /proc/asound/PandaBoardES/pcm0p/sub0 $ cat sw_params
liquid@fragile /proc/asound/PandaBoardES/pcm0p/sub0 $ cat status
owner_pid : 1845
tstamp : 2151.040465291
delay : 15098
avail : 1286
avail_max : 11266
hw_ptr : 4756742
appl_ptr : 4771840
Created attachment 114181 [details]
full kernel log
It looks like a feature. The reply from Peter Ujfalusi at alsa-devel ML:
Platforms using McPDM+twl6040 codec (OMAP4/5) supports 96KHz only at the moment.
This is hardware limitation and the only way to get 44.1/48 KHz supported is
to use AESS on these platforms. Unfortunately I only have AESS support out of
tree in my personal branch since it has dependency on Liam's out of tree
dynamic firmware set (which I'm rolling from kernel version to kernel version).
To use AESS one need to have the firmware as well which is again not upstream
I only have 3.12-rc1 based version of AESS support, but I'm planning to have
one for 3.12 and also for 3.13-rc1 when it comes out.