target/linux/bcm27xx/patches-5.15/950-0654-drm-vc4-Disable-Gamma-control-on-HVS5-due-to-issues-.patch

   1 From 6c276e5d2c0ee362e4b860845401e095773fad7f Mon Sep 17 00:00:00 2001
   2 From: Dave Stevenson <dave.stevenson@raspberrypi.com>
   3 Date: Thu, 13 Jan 2022 11:30:42 +0000
   4 Subject: [PATCH] drm/vc4: Disable Gamma control on HVS5 due to issues
   5  writing the table
   6
   7 Still under investigation, but the conditions under which the HVS
   8 will accept values written to the gamma PWL are not straightforward.
   9
  10 Disable gamma on HVS5 again until it can be resolved to avoid
  11 gamma being enabled with an incorrect table.
  12
  13 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
  14 ---
  15  drivers/gpu/drm/vc4/vc4_crtc.c | 8 +-------
  16  1 file changed, 1 insertion(+), 7 deletions(-)
  17
  18 --- a/drivers/gpu/drm/vc4/vc4_crtc.c
  19 +++ b/drivers/gpu/drm/vc4/vc4_crtc.c
  20 @@ -1182,15 +1182,9 @@ int vc4_crtc_init(struct drm_device *drm
  21
  22         if (!vc4->hvs->hvs5) {
  23                 drm_mode_crtc_set_gamma_size(crtc, ARRAY_SIZE(vc4_crtc->lut_r));
  24 -       } else {
  25 -               /* This is a lie for hvs5 which uses a 16 point PWL, but it
  26 -                * allows for something smarter than just 16 linearly spaced
  27 -                * segments. Conversion is done in vc5_hvs_update_gamma_lut.
  28 -                */
  29 -               drm_mode_crtc_set_gamma_size(crtc, 256);
  30 +               drm_crtc_enable_color_mgmt(crtc, 0, false, crtc->gamma_size);
  31         }
  32
  33 -       drm_crtc_enable_color_mgmt(crtc, 0, false, crtc->gamma_size);
  34
  35         if (!vc4->hvs->hvs5) {
  36                 /* We support CTM, but only for one CRTC at a time. It's therefore