[alsa-devel] [PATCH] ASoC: tegra: use dmaengine based dma driver

Stephen Warren swarren at wwwdotorg.org
Fri Jun 29 19:02:01 CEST 2012

On 06/29/2012 05:34 AM, Laxman Dewangan wrote:
> Use the dmaengine based Tegra APB DMA driver for
> data transfer between SPI fifo and memory in
> place of legacy Tegra APB DMA.
> Because generic soc-dmaengine-pcm uses the DMAs API
> based on dmaengine, using the exported APIs provided
> by this generic driver.
> The new driver is selected if legacy driver is not
> selected and new dma driver is enabled through config
> file.

This works just fine with the existing non-dmaengine DMA driver enabled.

However, I can't get it to work with dmaengine:

> # aplay ~/abba-dq-48000-stereo.wav
> [  151.613476] tegra20-i2s tegra20-i2s.0: dmaengine pcm open failed with err -6
> [  151.620557] tegra20-i2s tegra20-i2s.0: can't open platform tegra20-i2s.0: -6
> aplay: main:654: audio open error: No such device or address

I do have the following in my local tree:
68a67b8 ARM: tegra: add device tree AUXDATA for APBDMA
0db7a96 ARM: tegra: dma: rename driver name for clock to "tegra-apbdma"

I also fixed the compatible values in drivers/dma/tegra20-apb-dma.c so
the driver would get instantiated, which it does;
/sys/devices/tegra-apbdma/dma has a bunch of dmaengine channels in it.

(Note: This is on Ventana, although I doubt that makes much difference)

Is there something else I need to do to test this?

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