[PATCH AUTOSEL 4.19 16/27] omap-dma/omap_vout_vrfb: fix off-by-one fi value

Sasha Levin
2019-08-20T13:42:38Z

From: Hans Verkuil <hverkuil@xs4all.nl>

[ Upstream commit d555c34338cae844b207564c482e5a3fb089d25e ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/dma/ti/omap-dma.c | 4 ++--
drivers/media/platform/omap/omap_vout_vrfb.c | 3 +--
2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/dma/ti/omap-dma.c b/drivers/dma/ti/omap-dma.c
index a4a931ddf6f69..aeb9c29e52554 100644
--- a/drivers/dma/ti/omap-dma.c
+++ b/drivers/dma/ti/omap-dma.c
@@ -1237,7 +1237,7 @@ 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;
@@ -1252,7 +1252,7 @@ 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;
diff --git a/drivers/media/platform/omap/omap_vout_vrfb.c b/drivers/media/platform/omap/omap_vout_vrfb.c
index 29e3f5da59c1f..11ec048929e80 100644
--- a/drivers/media/platform/omap/omap_vout_vrfb.c
+++ b/drivers/media/platform/omap/omap_vout_vrfb.c
@@ -253,8 +253,7 @@ int omap_vout_prepare_vrfb(struct omap_vout_device *vout,
*/

pixsize = vout->bpp * vout->vrfb_bpp;
- dst_icg = ((MAX_PIXELS_PER_LINE * pixsize) -
- (vout->pix.width * vout->bpp)) + 1;
+ dst_icg = MAX_PIXELS_PER_LINE * pixsize - vout->pix.width * vout->bpp;

xt->src_start = vout->buf_phy_addr[vb->i];
xt->dst_start = vout->vrfb_context[vb->i].paddr[0];
--
2.20.1