[PATCH] dma: edma: add device_slave_caps() support

Lars-Peter Clausen lars at metafoo.de
Wed Jul 24 04:03:30 EDT 2013


On 07/23/2013 06:43 PM, Joel Fernandes wrote:
> Implement device_slave_caps(). EDMA has a limited number of slots.
> Slave drivers such as omap_hsmmc will query the driver to make
> sure they don't pass in more than these many scatter segments.
> 
> Signed-off-by: Joel Fernandes <joelf at ti.com>
> ---
> Vinod, or Dan- If this patch looks ok, can you please merge in for
> -rc cycle? This patch is required to fix MMC support on AM33xx. This
> patch is blocking 3 other patches which fix various MMC things. Thanks!
> 
> Notes:
> (1) this approach is temporary and only for -rc cycle to fix MMC on
> AM335x. It will be replace by the RFC series in future kernels:
> http://www.spinics.net/lists/arm-kernel/msg260094.html
> 
> (2) Patch depends Vinod's patch at:
> http://permalink.gmane.org/gmane.linux.kernel/1525112
> 
>  drivers/dma/edma.c |    9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c
> index 7222cbe..81d5429 100644
> --- a/drivers/dma/edma.c
> +++ b/drivers/dma/edma.c
> @@ -517,6 +517,14 @@ static void edma_issue_pending(struct dma_chan *chan)
>  	spin_unlock_irqrestore(&echan->vchan.lock, flags);
>  }
>  
> +static inline int edma_slave_caps(struct dma_chan *chan,
> +	struct dma_slave_caps *caps)
> +{
> +	caps->max_sg_nr = MAX_NR_SG;

Hm, what about the other fields?

- Lars




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