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, pre-filling the dma_slave_caps struct with what
it knows about the dma controller, before calling the dma_device callback, both
to maintain a backward compatibility and to make sure that drivers can override
that generic behaviour.
Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
---
include/linux/dmaengine.h | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 4d0294ec3567..cfcbee145898 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -772,17 +772,24 @@ 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)
{
+ 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 (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;
+
+ if (device->device_slave_caps)
+ return device->device_slave_caps(chan, caps);
- return -ENXIO;
+ return 0;
}
static inline int dmaengine_terminate_all(struct dma_chan *chan)
--
2.1.0
--
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
