Re: [PATCH 0/4] dmaengine: qcom: bam_dma: fixes for remotely controlled bam

[Srinivas Kandagatla]

On 17/01/18 10:18, Vinod Koul wrote:
> On Tue, Jan 16, 2018 at 07:02:32PM +0000, srinivas.kandagatla@xxxxxxxxxx wrote:
> > From: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> >
> > Hi Andy,
> >
> > I did hit few issues while trying out SLIMBus BAM on DB820c, this BAM instance
> > is remotely controlled and powered up after ADSP is booted using QMI commands.
>
> What do you mean by "remotely controlled" in this series?

DMA controller is controlled by the remote processor, which is a DSP in 
this case.
Linux side is in remote mode in this setup, this can setup transfer 
descriptors and start/stop a transfer. But all the 
initialization/powerup part will be done in the remote processor.

--srini

> > Firstly some of the master registers are written even when the BAM is remotely
> > controlled, and secondly reading registers when bam is not ready yet.
> >
> > These 4 patches address these issues, there are few more issues like doing PM
> > in simillar usecase, these will be addressed soon.
> >
> > Thanks,
> > Srini
> >
> > Srinivas Kandagatla (4):
> >    dmaengine: qcom: bam_dma: make bam clk optional
> >    dmaengine: qcom: bam_dma: add num-channels binding for remotely
> >      controlled
> >    dmaengine: qcom: bam_dma: do not write to global regs in remote mode
> >    dmaengine: qcom: bam_dma: Add num-ees dt binding for remotely
> >      controlled
> >
> >   .../devicetree/bindings/dma/qcom_bam_dma.txt       |  4 ++
> >   drivers/dma/qcom/bam_dma.c                         | 56 +++++++++++++++-------
> >   2 files changed, 43 insertions(+), 17 deletions(-)
> >
> > --
> > 2.15.1