[alsa-devel] ALSA - Channel swap

[Daniel Mack]

On 08/20/2014 02:37 PM, Tomas Matejka wrote:
> My kernel version is 3.2.18.
> I can't uderstand this, does this mean that using Atmel, Linux and audio 
> codec always result to channel swapping?
> It would be very strange. How could codec manufacturer sell codec, which 
> swaps channels ?

Also, as I've told you before, the Codec is most probably not the
cultprit here. Try and play a wave file that only has signal on the left
side, and provide some input to the Codec's left channel only. Then see
what your scope shows on the SDIN/SDOUT lines, while putting the trigger
on the LRCLK. If your Codec is causing the problem, you'll already see
the channel swap on the bus, but I bet you won't. Instead, the problem
is in how the Atmel I2S hardware block transports the data into and out
of your memory, and that's likely related to its DMA implementation.

Anyway - the first step is to boot an up-to-date kernel.


Daniel