[alsa-devel] [PATCH 1/7 v2] dmaengine: add a simple dma library

Shimoda, Yoshihiro yoshihiro.shimoda.uh at renesas.com
Fri Feb 3 09:47:48 CET 2012

Hi Guennadi-san,

2012/02/03 7:19, Guennadi Liakhovetski wrote:
[ snip ]
>> Thank you for your comment.
>> I investigaed the issue. I found out the renesas_usbhs driver may
>> call tx_submit() in the callback() of the dma-simple finally.
> Sorry, in my first reply to this your email I misread the renesas_usbhs 
> for an issue with your new SUDMAC driver. Since this is not the case and 
> my patch seems to be causing a regression, I'll look at it.

Thank you for the comment.

I found out that if the "power_up" is 0 in the sample_tx_submit(),
the pm_state will be changed to "PENDING".
And then, even if the renesas_usbhs calls dma_async_issue_pending(),
the dma-simple driver doesn't call the simple_chan_xfer_ld_queue().
This is because the driver will call the simple_chan_xfer_ld_queue()
when the pm_state is "ESTABLISHED" only.

So I guess that we have to modify the simple_issue_pending().

Best regards,
Yoshihiro Shimoda

> Thanks
> Guennadi
> ---
> Guennadi Liakhovetski, Ph.D.
> Freelance Open-Source Software Developer
> http://www.open-technology.de/
Yoshihiro Shimoda <yoshihiro.shimoda.uh at renesas.com>

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