sDMA on i.mx7d

[Alexandre Belloni]

On 14/02/2017 at 23:25:34 -0800, Stefan Agner wrote:
> On 2017-02-14 14:24, Alexandre Belloni wrote:
> > Hi,
> > 
> > I've been trying to get a PCM3168s codec with a Colibri iMX7 using TDM
> > on SAI2.
> > I've got it working properly with the 4.1.35 kernel from Toradex (based
> > on the 4.1.15 from Freescale).
> > It is working fine with and without providing a firmware to the sDMA.
> > 
> > But, I couldn't get that to work with v4.9. I actually managed to
> > reproduce the issue using the SGTL5000 so I don't have any patch on top
> > of v4.9.
> 
> I guess you are using the on module SGTL5000 to reproduce?
> 

Yes, using the on module sgtl5000 of a colibri on an iris.

> When I added audio support I remember that the sound seemed to be ok to
> me. Is the corruption such that you can hear it?
> 

You can hear it but not if you are playing a simple sine at a frequency
that is a multiple of 10 (e.g. 440Hz)

> > I really suspect the DMA driver as the issue varies with the selected
> > period/buffer size.
> > 
> > Basically, the samples in a period are in the correct order but the
> > periods are mixed up.
> 
> Maybe a endian issue?
> 

I don't think so.


-- 
Alexandre Belloni, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com