On Wed, 07 Nov 2018 09:08:02 -0800 Eric Anholt eric@anholt.net wrote:
Boris Brezillon boris.brezillon@bootlin.com writes:
On Wed, 24 Oct 2018 12:05:03 +0200 Boris Brezillon boris.brezillon@bootlin.com wrote:
The source image might be only vertically scaled, and in this case ->is_unity will be false, but we'd still have to force ->x_scaling[0] to VC4_SCALING_PPF for YUV conversion to work properly.
Let's replace the ->is_unity test by->x_scaling[0] == VC4_SCALING_NONE to cope with that.
Fixes: 658d8cbd07da ("drm/vc4: Fix the "no scaling" case on multi-planar YUV formats") Cc: stable@vger.kernel.org Signed-off-by: Boris Brezillon boris.brezillon@bootlin.com
drivers/gpu/drm/vc4/vc4_plane.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/vc4/vc4_plane.c b/drivers/gpu/drm/vc4/vc4_plane.c index 60d5ad19cedd..32b7b9f47c5d 100644 --- a/drivers/gpu/drm/vc4/vc4_plane.c +++ b/drivers/gpu/drm/vc4/vc4_plane.c @@ -318,7 +318,7 @@ static int vc4_plane_setup_clipping_and_scaling(struct drm_plane_state *state) * even on a plane that's otherwise 1:1. Looks like only PPF * works in that case, so let's pick that one. */
if (vc4_state->is_unity)
if (vc4_state->x_scaling[0] == VC4_SCALING_NONE) vc4_state->x_scaling[0] = VC4_SCALING_PPF;Actually, I'm not sure about this patch is needed. According to the spec, we should not enable the scaler on the Y channel when ->is_unity is true. I tested it, and it seems to work if we just leave x_scaling[0] to VC4_SCALING_NONE.
Sorry, I've been delaying on this series until I could spend some time looking at the spec.
I think you're right, I see no reason to kick us out of is_unity for YUV -- you can have is_unity, Y unscaled, and UV scaled.
Okay, so I'll just remove
if (vc4_state->x_scaling[0] == VC4_SCALING_NONE) vc4_state->x_scaling[0] = VC4_SCALING_PPF;
What about the 2 other patches in this series? Patch 2 is fixing a real bug, patch 3 is not fixing a bug, but according to the spec PPF is better when the downscaling ratio is small.