Commit 0560054d authored by Boris Brezillon's avatar Boris Brezillon

drm/vc4: ->x_scaling[1] should never be set to VC4_SCALING_NONE

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: fc04023f ("drm/vc4: Add support for YUV planes.")
Signed-off-by: default avatarBoris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: default avatarEric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20181109102633.32603-1-boris.brezillon@bootlin.com
parent 65bf2d54
...@@ -341,12 +341,14 @@ static int vc4_plane_setup_clipping_and_scaling(struct drm_plane_state *state) ...@@ -341,12 +341,14 @@ static int vc4_plane_setup_clipping_and_scaling(struct drm_plane_state *state)
vc4_get_scaling_mode(vc4_state->src_h[1], vc4_get_scaling_mode(vc4_state->src_h[1],
vc4_state->crtc_h); vc4_state->crtc_h);
/* YUV conversion requires that horizontal scaling be enabled, /* YUV conversion requires that horizontal scaling be enabled
* even on a plane that's otherwise 1:1. Looks like only PPF * on the UV plane even if vc4_get_scaling_mode() returned
* works in that case, so let's pick that one. * 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) if (vc4_state->x_scaling[1] == VC4_SCALING_NONE)
vc4_state->x_scaling[0] = VC4_SCALING_PPF; vc4_state->x_scaling[1] = VC4_SCALING_PPF;
} else { } else {
vc4_state->is_yuv = false; vc4_state->is_yuv = false;
vc4_state->x_scaling[1] = VC4_SCALING_NONE; vc4_state->x_scaling[1] = VC4_SCALING_NONE;
......
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