Hi Maxime,
Thank you for the patch.
On Thursday 16 October 2014 12:17:05 Maxime Ripard wrote:
> dma_slave_caps is very important to the generic layers that might interact
> with dmaengine, such as ASoC. Unfortunately, it has been added as yet
> another dma_device callback, and most of the existing drivers haven't
> implemented it, reducing its reliability.
>
> Introduce a generic behaviour and a flag to trigger it. In case this flag
> hasn't been set, fall back to the old mechanism.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
> ---
> include/linux/dmaengine.h | 25 +++++++++++++++++++++----
> 1 file changed, 21 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
> index 4d0294ec3567..85afd71df2e7 100644
> --- a/include/linux/dmaengine.h
> +++ b/include/linux/dmaengine.h
> @@ -643,6 +643,8 @@ struct dma_device {
> int dev_id;
> struct device *dev;
>
> + bool generic_slave_caps;
> +
> int (*device_alloc_chan_resources)(struct dma_chan *chan);
> void (*device_free_chan_resources)(struct dma_chan *chan);
>
> @@ -772,17 +774,32 @@ static inline struct dma_async_tx_descriptor
> *dmaengine_prep_interleaved_dma(
>
> static inline int dma_get_slave_caps(struct dma_chan *chan, struct
> dma_slave_caps *caps) {
This is getting too big for an inline function, it should be moved to
drivers/dma/dmaengine.c.
> + struct dma_device *device;
> +
> if (!chan || !caps)
> return -EINVAL;
>
> + device = chan->device;
> +
> /* check if the channel supports slave transactions */
> - if (!test_bit(DMA_SLAVE, chan->device->cap_mask.bits))
> + if (!test_bit(DMA_SLAVE, device->cap_mask.bits))
> + return -ENXIO;
> +
> + if (device->device_slave_caps)
> + return device->device_slave_caps(chan, caps);
> +
> + /*
> + * Check whether it reports it uses the generic slave
> + * capabilities, if not, that means it doesn't support any
> + * kind of slave capabilities reporting.
> + */
> + if (device->generic_slave_caps)
> return -ENXIO;
Couldn't we replace that check with if (device->device_control) and get rid of
the generic_slave_caps field ? Drivers converted to the new API would then get
slave caps support for free.
> - if (chan->device->device_slave_caps)
> - return chan->device->device_slave_caps(chan, caps);
> + caps->cmd_pause = !!device->device_pause;
> + caps->cmd_terminate = !!device->device_terminate_all;
>
> - return -ENXIO;
> + return 0;
> }
>
> static inline int dmaengine_terminate_all(struct dma_chan *chan)
--
Regards,
Laurent Pinchart
--
To unsubscribe from this list: send the line "unsubscribe dmaengine" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
