linux/drivers/dma/ti
Hans Verkuil d555c34338 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>
2019-08-09 16:33:41 +05:30
..
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile
cppi41.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
dma-crossbar.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
edma.c
omap-dma.c omap-dma/omap_vout_vrfb: fix off-by-one fi value 2019-08-09 16:33:41 +05:30