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>
Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
Tested-by: Mathieu Malaterre <malat@xxxxxxxxxx>
---
Notes:
v2: No change
v3: No change
v4: Add my Signed-off-by
v5: Use GENMASK macro
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 3a4d0a4b550d..bd3cecb800c5 100644
--- a/drivers/dma/dma-jz4780.c
+++ b/drivers/dma/dma-jz4780.c
@@ -616,7 +616,8 @@ 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 & GENMASK(23, 0)) <<
+ jzchan->transfer_shift;
if (next_sg != 0) {
count = jz4780_dma_chn_readl(jzdma, jzchan->id,
--
2.11.0
