Re: [PATCH v2 04/53] dmaengine: split out pause/resume operations from device_control

[Laurent Pinchart]

Hi Maxime,

Thank you for the patch.

On Thursday 16 October 2014 12:17:03 Maxime Ripard wrote:
> Split out the pause and resume operations to callbacks of their own. In
> order to preserve some backwark compatibility, the
> dmaengine_pause/dmaengine_resume are still falling back on
> dmaengine_device_control.
> 
> Hopefully, that will allow to get the device capabilities in a generic way,
> removing the need to implement device_slave_caps.

Instead of being hopeful let's implement that ;-)

> Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>

Acked-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>

> ---
>  include/linux/dmaengine.h | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
> index 7937f81e5e2e..b89c8004fcd8 100644
> --- a/include/linux/dmaengine.h
> +++ b/include/linux/dmaengine.h
> @@ -612,6 +612,10 @@ struct dma_tx_state {
>   *	code
>   * @device_control: manipulate all pending operations on a channel, returns
> *	zero or error code
> + * @device_pause: Pauses any transfer happening on a channel. Returns
> + *	0 or an error code
> + * @device_resume: Resumes any transfer on a channel previously
> + *	paused. Returns 0 or an error code
>   * @device_tx_status: poll for transaction completion, the optional
>   *	txstate parameter can be supplied with a pointer to get a
>   *	struct with auxiliary transfer status information, otherwise the call
> @@ -680,6 +684,8 @@ struct dma_device {
>  			     struct dma_slave_config *config);
>  	int (*device_control)(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
>  			      unsigned long arg);
> +	int (*device_pause)(struct dma_chan *chan);
> +	int (*device_resume)(struct dma_chan *chan);
>  	enum dma_status (*device_tx_status)(struct dma_chan *chan,
>  					    dma_cookie_t cookie,
>  					    struct dma_tx_state *txstate);
> @@ -783,11 +789,17 @@ static inline int dmaengine_terminate_all(struct
> dma_chan *chan)
> 
>  static inline int dmaengine_pause(struct dma_chan *chan)
>  {
> +	if (chan->device->device_pause)
> +		return chan->device->device_pause(chan);
> +
>  	return dmaengine_device_control(chan, DMA_PAUSE, 0);
>  }
> 
>  static inline int dmaengine_resume(struct dma_chan *chan)
>  {
> +	if (chan->device->device_resume)
> +		return chan->device->device_resume(chan);
> +
>  	return dmaengine_device_control(chan, DMA_RESUME, 0);
>  }

-- 
Regards,

Laurent Pinchart

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