4.20-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 0560054da5673b25d56bea6c57c8d069673af73b ]
For the YUV conversion to work properly, ->x_scaling[1] should never be set to VC4_SCALING_NONE, but vc4_get_scaling_mode() might return VC4_SCALING_NONE if the horizontal scaling ratio exactly matches the horizontal subsampling factor. Add a test to turn VC4_SCALING_NONE into VC4_SCALING_PPF when that happens.
The old ->x_scaling[0] adjustment is dropped as I couldn't find any mention to this constraint in the spec and it's proven to be unnecessary (I tested various multi-planar YUV formats with scaling disabled, and all of them worked fine without this adjustment).
Fixes: fc04023fafec ("drm/vc4: Add support for YUV planes.") Signed-off-by: Boris Brezillon boris.brezillon@bootlin.com Reviewed-by: Eric Anholt eric@anholt.net Link: https://patchwork.freedesktop.org/patch/msgid/20181109102633.32603-1-boris.b... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/vc4/vc4_plane.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/vc4/vc4_plane.c b/drivers/gpu/drm/vc4/vc4_plane.c index ae6254b0b1ae..ed8b0fc170ee 100644 --- a/drivers/gpu/drm/vc4/vc4_plane.c +++ b/drivers/gpu/drm/vc4/vc4_plane.c @@ -314,12 +314,14 @@ static int vc4_plane_setup_clipping_and_scaling(struct drm_plane_state *state) vc4_get_scaling_mode(vc4_state->src_h[1], vc4_state->crtc_h);
- /* YUV conversion requires that horizontal scaling be enabled, - * even on a plane that's otherwise 1:1. Looks like only PPF - * works in that case, so let's pick that one. + /* YUV conversion requires that horizontal scaling be enabled + * on the UV plane even if vc4_get_scaling_mode() returned + * VC4_SCALING_NONE (which can happen when the down-scaling + * ratio is 0.5). Let's force it to VC4_SCALING_PPF in this + * case. */ - if (vc4_state->is_unity) - vc4_state->x_scaling[0] = VC4_SCALING_PPF; + if (vc4_state->x_scaling[1] == VC4_SCALING_NONE) + vc4_state->x_scaling[1] = VC4_SCALING_PPF; } else { vc4_state->is_yuv = false; vc4_state->x_scaling[1] = VC4_SCALING_NONE;