2014-04-28 20:49:47

by Joel Fernandes

Subject: [PATCH 1/2] dmaengine: edma: Document variables used for residue accounting

The granular residue accounting code uses certain variables specifically
for residue accounting. Document these in the structure declaration.
Also move around some elements and group them together.

Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Joel Fernandes <[email protected]>
---
drivers/dma/edma.c | 26 ++++++++++++++++++++++++--
1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c
index 4c574f60..8926078 100644
--- a/drivers/dma/edma.c
+++ b/drivers/dma/edma.c
@@ -70,12 +70,34 @@ struct edma_desc {
int cyclic;
int absync;
int pset_nr;
+ struct edma_chan *echan;
int processed;
+
+ /*
+ * The following 4 elements are used for residue accounting.
+ *
+ * - processed_stat: the number of SG elements we have traversed
+ * so far to cover accounting. This is updated directly to processed
+ * during edma_callback and is always <= processed, because processed
+ * refers to the number of pending transfer (programmed to EDMA
+ * controller), where as processed_stat tracks number of transfers
+ * accounted for so far.
+ *
+ * - residue: The amount of bytes we have left to transfer for this desc
+ *
+ * - residue_stat: The residue in bytes of data we have covered
+ * so far for accounting. This is updated directly to residue
+ * during callbacks to keep it current.
+ *
+ * - sg_len: Tracks the length of the current intermediate transfer,
+ * this is required to update the residue during intermediate transfer
+ * completion callback.
+ */
int processed_stat;
- u32 residue;
u32 sg_len;
+ u32 residue;
u32 residue_stat;
- struct edma_chan *echan;
+
struct edma_pset pset[0];
};

--
1.7.9.5

2014-04-28 20:49:43

by Joel Fernandes

Subject: [PATCH 2/2] dmaengine: edma: update DMA memcpy to use new param element

edma param struct is now within an edma_pset struct introduced in Thomas
Gleixner's edma tx status series. Update memcpy function for the same.

Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Joel Fernandes <[email protected]>
---
drivers/dma/edma.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c
index 8926078..ec9c410 100644
--- a/drivers/dma/edma.c
+++ b/drivers/dma/edma.c
@@ -582,8 +582,8 @@ struct dma_async_tx_descriptor *edma_prep_dma_memcpy(
* on completion of every TR, and enable transfer-completion
* interrupt on completion of the whole transfer.
*/
- edesc->pset[0].opt |= ITCCHEN;
- edesc->pset[0].opt |= TCINTEN;
+ edesc->pset[0].param.opt |= ITCCHEN;
+ edesc->pset[0].param.opt |= TCINTEN;

return vchan_tx_prep(&echan->vchan, &edesc->vdesc, tx_flags);
}
--
1.7.9.5