[PATCH 5.10 189/545] drm/vc4: plane: Remove subpixel positioning check

Greg Kroah-Hartman
2022-08-19T16:11:45Z

From: Dom Cobley <popcornmix@gmail.com>

[ Upstream commit 517db1ab1566dba3093dbdb8de4263ba4aa66416 ]

There is little harm in ignoring fractional coordinates
(they just get truncated).

Without this:
modetest -M vc4 -F tiles,gradient -s 32:1920x1080-60 -P89@74:1920x1080*.1.1@XR24

is rejected. We have the same issue in Kodi when trying to
use zoom options on video.

Note: even if all coordinates are fully integer. e.g.
src:[0,0,1920,1080] dest:[-10,-10,1940,1100]

it will still get rejected as drm_atomic_helper_check_plane_state
uses drm_rect_clip_scaled which transforms this to fractional src coords

Fixes: 21af94cf1a4c ("drm/vc4: Add support for scaling of display planes.")
Signed-off-by: Dom Cobley <popcornmix@gmail.com>
Link: https://lore.kernel.org/r/20220613144800.326124-5-maxime@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/vc4/vc4_plane.c | 22 +++++++++-------------
1 file changed, 9 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_plane.c b/drivers/gpu/drm/vc4/vc4_plane.c
index af4b8944a603..bdf16554cf68 100644
--- a/drivers/gpu/drm/vc4/vc4_plane.c
+++ b/drivers/gpu/drm/vc4/vc4_plane.c
@@ -332,7 +332,6 @@ static int vc4_plane_setup_clipping_and_scaling(struct drm_plane_state *state)
struct vc4_plane_state *vc4_state = to_vc4_plane_state(state);
struct drm_framebuffer *fb = state->fb;
struct drm_gem_cma_object *bo = drm_fb_cma_get_gem_obj(fb, 0);
- u32 subpixel_src_mask = (1 << 16) - 1;
int num_planes = fb->format->num_planes;
struct drm_crtc_state *crtc_state;
u32 h_subsample = fb->format->hsub;
@@ -354,18 +353,15 @@ static int vc4_plane_setup_clipping_and_scaling(struct drm_plane_state *state)
for (i = 0; i < num_planes; i++)
vc4_state->offsets[i] = bo->paddr + fb->offsets[i];

- /* We don't support subpixel source positioning for scaling. */
- if ((state->src.x1 & subpixel_src_mask) ||
- (state->src.x2 & subpixel_src_mask) ||
- (state->src.y1 & subpixel_src_mask) ||
- (state->src.y2 & subpixel_src_mask)) {
- return -EINVAL;
- }
-
- vc4_state->src_x = state->src.x1 >> 16;
- vc4_state->src_y = state->src.y1 >> 16;
- vc4_state->src_w[0] = (state->src.x2 - state->src.x1) >> 16;
- vc4_state->src_h[0] = (state->src.y2 - state->src.y1) >> 16;
+ /*
+ * We don't support subpixel source positioning for scaling,
+ * but fractional coordinates can be generated by clipping
+ * so just round for now
+ */
+ vc4_state->src_x = DIV_ROUND_CLOSEST(state->src.x1, 1 << 16);
+ vc4_state->src_y = DIV_ROUND_CLOSEST(state->src.y1, 1 << 16);
+ vc4_state->src_w[0] = DIV_ROUND_CLOSEST(state->src.x2, 1 << 16) - vc4_state->src_x;
+ vc4_state->src_h[0] = DIV_ROUND_CLOSEST(state->src.y2, 1 << 16) - vc4_state->src_y;

vc4_state->crtc_x = state->dst.x1;
vc4_state->crtc_y = state->dst.y1;
--
2.35.1