From 444884f7b62bfe5ef313dd1d47f81a40e695ab0b Mon Sep 17 00:00:00 2001 From: Dave Stevenson Date: Fri, 17 Nov 2023 14:43:44 +0000 Subject: [PATCH] drm/vc4: Drop planes that are completely off-screen It is permitted for a plane to be configured such that none of it is on-screen via either negative dest rectangle X,Y offset, or just an offset that is greater than the crtc dimensions. These planes were resized via drm_atomic_helper_check_plane_state such that the source rectangle had a zero width or height, but they still created a dlist entry even though they contributed no pixels. In the case of vc6_plane_mode_set, that it could result in negative values being written into registers, which caused incorrect behaviour. Drop planes that result in a source width or height of 0 pixels to avoid the incorrect rendering. Signed-off-by: Dave Stevenson --- drivers/gpu/drm/vc4/vc4_plane.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) --- a/drivers/gpu/drm/vc4/vc4_plane.c +++ b/drivers/gpu/drm/vc4/vc4_plane.c @@ -1108,6 +1108,12 @@ static int vc4_plane_mode_set(struct drm width = vc4_state->src_w[0] >> 16; height = vc4_state->src_h[0] >> 16; + if (!width || !height) { + /* 0 source size probably means the plane is offscreen */ + vc4_state->dlist_initialized = 1; + return 0; + } + /* SCL1 is used for Cb/Cr scaling of planar formats. For RGB * and 4:4:4, scl1 should be set to scl0 so both channels of * the scaler do the same thing. For YUV, the Y plane needs @@ -1623,6 +1629,12 @@ static int vc6_plane_mode_set(struct drm width = vc4_state->src_w[0] >> 16; height = vc4_state->src_h[0] >> 16; + if (!width || !height) { + /* 0 source size probably means the plane is offscreen */ + vc4_state->dlist_initialized = 1; + return 0; + } + /* SCL1 is used for Cb/Cr scaling of planar formats. For RGB * and 4:4:4, scl1 should be set to scl0 so both channels of * the scaler do the same thing. For YUV, the Y plane needs @@ -1994,6 +2006,9 @@ int vc4_plane_atomic_check(struct drm_pl if (ret) return ret; + if (!vc4_state->src_w[0] || !vc4_state->src_h[0]) + return 0; + ret = vc4_plane_allocate_lbm(new_plane_state); if (ret) return ret;