Re: [PATCH] ASoC: tegra: use dmaengine based dma driver

[Laxman Dewangan]

On Saturday 30 June 2012 08:38 PM, Laxman Dewangan wrote:
> On Friday 29 June 2012 10:32 PM, Stephen Warren wrote:
> > 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
> With the error, it seems that dmachannel is not getting allocated.
>
> > 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"
> Some dma changes which I sent and already on linux-next are also require
> with the above change.
> Alsong with that I have local change like to rename the dma driver to
> compatible with dts files (remove -new from driver).
>
> I think I should send that patches so that you can test it by:
> - Taking already applied dma driver change in linux-next.
> - Apply my new patches which I am going to send.
>
> And do local change in the tegra_defconfig to disable SYSTEM_DMA and
> enable dmaengine based dma driver.
The new dma patches are:

 dma: tegra: fix residual calculation for cyclic case
 dma: tegra: rename driver and compatible to match with dts

You require dma changes which is already in linux-next:

 dma: tegra: set DMA_CYCLIC capability
 dma: tegra: do not set transfer desc flag to DMA_CTRL_ACK in cyclic mode
 dma: tegra: add clk_prepare/clk_unprepare
 dma: tegra: use sg_dma_address() for getting dma buffer address
 dma: tegra: add dmaengine based dma driver



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