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authorHans Verkuil <hverkuil@xs4all.nl>2019-08-09 10:32:40 +0200
committerVinod Koul <vkoul@kernel.org>2019-08-09 16:33:41 +0530
commitd555c34338cae844b207564c482e5a3fb089d25e (patch)
tree896e40b9cdd7fdbcdfd524a732daccab82beaa5d /drivers/dma
parent39c71a5b8212f4b502d9a630c6706ac723abd422 (diff)
downloadlinux-d555c34338cae844b207564c482e5a3fb089d25e.tar.bz2
omap-dma/omap_vout_vrfb: fix off-by-one fi value
The OMAP 4 TRM specifies that when using double-index addressing the address increases by the ES plus the EI value minus 1 within a frame. When a full frame is transferred, the address increases by the ES plus the frame index (FI) value minus 1. The omap-dma code didn't account for the 'minus 1' in the FI register. To get correct addressing, add 1 to the src_icg value. This was found when testing a hacked version of the media m2m-deinterlace.c driver on a Pandaboard. The only other source that uses this feature is omap_vout_vrfb.c, and that adds a + 1 when setting the dst_icg. This is a workaround for the broken omap-dma.c behavior. So remove the workaround at the same time that we fix omap-dma.c. I tested the omap_vout driver with a Beagle XM board to check that the '+ 1' in omap_vout_vrfb.c was indeed a workaround for the omap-dma bug. Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Acked-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Link: https://lore.kernel.org/r/952e7f51-f208-9333-6f58-b7ed20d2ea0b@xs4all.nl Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/ti/omap-dma.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/dma/ti/omap-dma.c b/drivers/dma/ti/omap-dma.c
index ba2489d4ea24..ba27802efcd0 100644
--- a/drivers/dma/ti/omap-dma.c
+++ b/drivers/dma/ti/omap-dma.c
@@ -1234,7 +1234,7 @@ static struct dma_async_tx_descriptor *omap_dma_prep_dma_interleaved(
if (src_icg) {
d->ccr |= CCR_SRC_AMODE_DBLIDX;
d->ei = 1;
- d->fi = src_icg;
+ d->fi = src_icg + 1;
} else if (xt->src_inc) {
d->ccr |= CCR_SRC_AMODE_POSTINC;
d->fi = 0;
@@ -1249,7 +1249,7 @@ static struct dma_async_tx_descriptor *omap_dma_prep_dma_interleaved(
if (dst_icg) {
d->ccr |= CCR_DST_AMODE_DBLIDX;
sg->ei = 1;
- sg->fi = dst_icg;
+ sg->fi = dst_icg + 1;
} else if (xt->dst_inc) {
d->ccr |= CCR_DST_AMODE_POSTINC;
sg->fi = 0;