From mboxrd@z Thu Jan 1 00:00:00 1970 From: stefan@agner.ch (Stefan Agner) Date: Tue, 14 Feb 2017 23:25:34 -0800 Subject: sDMA on i.mx7d In-Reply-To: <20170214222425.hbkfkeq3l6sveo7n@piout.net> References: <20170214222425.hbkfkeq3l6sveo7n@piout.net> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Alexandre, 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? 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? > > 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? > > This is what I'm playing in a loop: > http://free-electrons.com/~alexandre/source.png > > This is the output I get: > http://free-electrons.com/~alexandre/playback.png > > The configuration for the cyclic transfer seems to be fine and I don't > know enough about the sdma to investigate further. > I can try to backport b7d2648ac3d4 "dmaengine: imx-sdma: Add i.MX7 > support" to v4.8 and test I you think that can be useful I'll do a test with v4.9 on Colibri iMX7 internal SGTL5000. -- Stefan