[PATCH 2/3] dmaengine: enable DMA_CTRL_REUSE

From: Robert Jarzmik
Date: Sun Sep 06 2015 - 07:46:40 EST


In the current state, the capability of transfer reuse can neither be
set by a slave dmaengine driver, nor used by a client driver, because
the capability is not available to dma_get_slave_caps().

Fix this by adding a way to declare the capability.

Fixes: 272420214d26 ("dmaengine: Add DMA_CTRL_REUSE")
Signed-off-by: Robert Jarzmik <robert.jarzmik@xxxxxxx>
---
drivers/dma/dmaengine.c | 1 +
include/linux/dmaengine.h | 2 ++
2 files changed, 3 insertions(+)

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 3ff284c8e3d5..bb33e2ff5a42 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -493,6 +493,7 @@ int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps)
caps->dst_addr_widths = device->dst_addr_widths;
caps->directions = device->directions;
caps->residue_granularity = device->residue_granularity;
+ caps->descriptor_reuse = device->descriptor_reuse;

/*
* Some devices implement only pause (e.g. to get residuum) but no
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index e2f5eb419976..71b95257d835 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -635,6 +635,7 @@ struct dma_tx_state {
* struct with auxiliary transfer status information, otherwise the call
* will just return a simple status code
* @device_issue_pending: push pending transactions to hardware
+ * @descriptor_reuse: a submitted transfer can be resubmitted after completion
*/
struct dma_device {

@@ -657,6 +658,7 @@ struct dma_device {
u32 src_addr_widths;
u32 dst_addr_widths;
u32 directions;
+ bool descriptor_reuse;
enum dma_residue_granularity residue_granularity;

int (*device_alloc_chan_resources)(struct dma_chan *chan);
--
2.1.4

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