[v3,11/18] dmaengine: dma-jz4780: Add missing residue DTC mask
diff mbox

Message ID 20180721110643.19624-12-paul@crapouillou.net
State Changes Requested
Headers show

Commit Message

Paul Cercueil July 21, 2018, 11:06 a.m. UTC
From: Daniel Silsby <dansilsby@gmail.com>

The 'dtc' word in jz DMA descriptors contains two fields: The
lowest 24 bits are the transfer count, and upper 8 bits are the DOA
offset to next descriptor. The upper 8 bits are now correctly masked
off when computing residue in jz4780_dma_desc_residue(). Note that
reads of the DTCn hardware reg are automatically masked this way.

Signed-off-by: Daniel Silsby <dansilsby@gmail.com>
Tested-by: Mathieu Malaterre <malat@debian.org>
---
 drivers/dma/dma-jz4780.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

 v2: No change

 v3: No change

Comments

Vinod Koul July 24, 2018, 1:38 p.m. UTC | #1
On 21-07-18, 13:06, Paul Cercueil wrote:
> From: Daniel Silsby <dansilsby@gmail.com>
> 
> The 'dtc' word in jz DMA descriptors contains two fields: The
> lowest 24 bits are the transfer count, and upper 8 bits are the DOA
> offset to next descriptor. The upper 8 bits are now correctly masked
> off when computing residue in jz4780_dma_desc_residue(). Note that
> reads of the DTCn hardware reg are automatically masked this way.
> 
> Signed-off-by: Daniel Silsby <dansilsby@gmail.com>
> Tested-by: Mathieu Malaterre <malat@debian.org>

This needs your s-o-b. Please see Documentation/process/submitting-patches.rst

I think Randy did flag this one some other patch as well. All the
patches need to be signed off by sender as well

Patch
diff mbox

diff --git a/drivers/dma/dma-jz4780.c b/drivers/dma/dma-jz4780.c
index 3c9d3952e23a..fa926de082ba 100644
--- a/drivers/dma/dma-jz4780.c
+++ b/drivers/dma/dma-jz4780.c
@@ -614,7 +614,8 @@  static size_t jz4780_dma_desc_residue(struct jz4780_dma_chan *jzchan,
 	residue = 0;
 
 	for (i = next_sg; i < desc->count; i++)
-		residue += desc->desc[i].dtc << jzchan->transfer_shift;
+		residue += (desc->desc[i].dtc & 0xffffff) <<
+			jzchan->transfer_shift;
 
 	if (next_sg != 0) {
 		count = jz4780_dma_chn_readl(jzdma, jzchan->id,