diff options
| author | Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> | 2020-04-07 17:44:17 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-06-22 09:05:13 +0200 |
| commit | 1bab4e0d4d1e0269cd67a96781389a2393b4a4b8 (patch) | |
| tree | 72c65022a436e1bd63ebe7fdec836dd0e30b0c46 /kernel | |
| parent | 5d9560f9d171612bd0a07c6754ac05d072ce0518 (diff) | |
media: platform: fcp: Set appropriate DMA parameters
[ Upstream commit dd844fb8e50b12e65bbdc5746c9876c6735500df ]
Enabling CONFIG_DMA_API_DEBUG=y and CONFIG_DMA_API_DEBUG_SG=y will
enable extra validation on DMA operations ensuring that the size
restraints are met.
When using the FCP in conjunction with the VSP1/DU, and display frames,
the size of the DMA operations is larger than the default maximum
segment size reported by the DMA core (64K). With the DMA debug enabled,
this produces a warning such as the following:
"DMA-API: rcar-fcp fea27000.fcp: mapping sg segment longer than device
claims to support [len=3145728] [max=65536]"
We have no specific limitation on the segment size which isn't already
handled by the VSP1/DU which actually handles the DMA allcoations and
buffer management, so define a maximum segment size of up to 4GB (a 32
bit mask).
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Fixes: 7b49235e83b2 ("[media] v4l: Add Renesas R-Car FCP driver")
Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel')
0 files changed, 0 insertions, 0 deletions