target/linux/bcm27xx/patches-6.1/950-1161-drm-vc4-Drop-planes-that-are-completely-off-screen.patch

   1 From 444884f7b62bfe5ef313dd1d47f81a40e695ab0b Mon Sep 17 00:00:00 2001
   2 From: Dave Stevenson <dave.stevenson@raspberrypi.com>
   3 Date: Fri, 17 Nov 2023 14:43:44 +0000
   4 Subject: [PATCH] drm/vc4: Drop planes that are completely off-screen
   5
   6 It is permitted for a plane to be configured such that none
   7 of it is on-screen via either negative dest rectangle X,Y
   8 offset, or just an offset that is greater than the crtc
   9 dimensions.
  10
  11 These planes were resized via drm_atomic_helper_check_plane_state
  12 such that the source rectangle had a zero width or height, but
  13 they still created a dlist entry even though they contributed
  14 no pixels. In the case of vc6_plane_mode_set, that it could result
  15 in negative values being written into registers, which caused
  16 incorrect behaviour.
  17
  18 Drop planes that result in a source width or height of 0 pixels
  19 to avoid the incorrect rendering.
  20
  21 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
  22 ---
  23  drivers/gpu/drm/vc4/vc4_plane.c | 15 +++++++++++++++
  24  1 file changed, 15 insertions(+)
  25
  26 --- a/drivers/gpu/drm/vc4/vc4_plane.c
  27 +++ b/drivers/gpu/drm/vc4/vc4_plane.c
  28 @@ -1108,6 +1108,12 @@ static int vc4_plane_mode_set(struct drm
  29         width = vc4_state->src_w[0] >> 16;
  30         height = vc4_state->src_h[0] >> 16;
  31
  32 +       if (!width || !height) {
  33 +               /* 0 source size probably means the plane is offscreen */
  34 +               vc4_state->dlist_initialized = 1;
  35 +               return 0;
  36 +       }
  37 +
  38         /* SCL1 is used for Cb/Cr scaling of planar formats.  For RGB
  39          * and 4:4:4, scl1 should be set to scl0 so both channels of
  40          * the scaler do the same thing.  For YUV, the Y plane needs
  41 @@ -1623,6 +1629,12 @@ static int vc6_plane_mode_set(struct drm
  42         width = vc4_state->src_w[0] >> 16;
  43         height = vc4_state->src_h[0] >> 16;
  44
  45 +       if (!width || !height) {
  46 +               /* 0 source size probably means the plane is offscreen */
  47 +               vc4_state->dlist_initialized = 1;
  48 +               return 0;
  49 +       }
  50 +
  51         /* SCL1 is used for Cb/Cr scaling of planar formats.  For RGB
  52          * and 4:4:4, scl1 should be set to scl0 so both channels of
  53          * the scaler do the same thing.  For YUV, the Y plane needs
  54 @@ -1994,6 +2006,9 @@ int vc4_plane_atomic_check(struct drm_pl
  55         if (ret)
  56                 return ret;
  57
  58 +       if (!vc4_state->src_w[0] || !vc4_state->src_h[0])
  59 +               return 0;
  60 +
  61         ret = vc4_plane_allocate_lbm(new_plane_state);
  62         if (ret)
  63                 return ret;