[PATCH 08/14] dmaengine: dma-jz4780: Add missing residue DTC mask

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Daniel Silsby <dansilsby@xxxxxxxxx>

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@xxxxxxxxx>
---
 drivers/dma/dma-jz4780.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/dma-jz4780.c b/drivers/dma/dma-jz4780.c
index 7ee2c121948f..7b2e305e28fb 100644
--- a/drivers/dma/dma-jz4780.c
+++ b/drivers/dma/dma-jz4780.c
@@ -610,7 +610,8 @@ 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,
-- 
2.18.0

--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Device Tree Compilter]     [Device Tree Spec]     [Linux Driver Backports]     [Video for Linux]     [Linux USB Devel]     [Linux PCI Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Yosemite Backpacking]


  Powered by Linux