[alsa-devel] iMX6 ESAI TDM with underrun and overrun support

[Fabio Estevam]

Hi Aurelien,

[Adding Nicolin and Mark on Cc]

On Wed, Dec 17, 2014 at 1:13 PM, Aurelien Bouin <a_bouin at yahoo.fr> wrote:
> Hello,
> I am currently working on an iMX6 board, I work with the master branch of git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
> I have seen some problems in the freescale ESAI implementation :
>
> 1.The registers TCCR and RCCR have TFP and RFP bits in register of a width of 5, not 4 !
> With a value of 5 we are able to use the full range of slots (32)
> Patch : http://pastebin.com/Ai1RZ9mE

Please send this as a formal patch for review in the list.

> 2.The channels number are limited in Playback to 12, but actually we can rise 128, in Capture it is limited to 8 but actually we can rise 128 also
>
> Patch : http://pastebin.com/SHk5eHPa

Same here.

>
> I use the iMX6 ESAI bus to send audio datas to other processors ... but actually I don't have any codec behind ...
> I am wondering if there is any solution with the devicetree to implement such configuration with "simple-audio-card"
>
> Because for the moment I have not find another solution than doing a module : http://pastebin.com/cnGwnEjn
>
> I also see that the chip errata of the iMX6 ERR008000 is not handle ...Which make channel swapping on my ESAI bus ...
> Is there someone that succeed in implementing the underrun overrun catch ?

Are you getting the "isr: Receiving overrun/underrun" warnings from
the esai driver?