target/linux/brcm2708/patches-4.4/0513-drm-vc4-Fix-up-the-limited-range-RGB-output-commit.patch

   1 From b66013edab6e2149beb55eb1021926fd7ea26da7 Mon Sep 17 00:00:00 2001
   2 From: Eric Anholt <eric@anholt.net>
   3 Date: Thu, 15 Sep 2016 17:52:17 +0100
   4 Subject: [PATCH] drm/vc4: Fix up the limited range RGB output commit.
   5
   6 CEA mode #1 is the only one that doesn't do limited range, thus the
   7 strange pattern in other drivers.
   8
   9 Signed-off-by: Eric Anholt <eric@anholt.net>
  10 ---
  11  drivers/gpu/drm/vc4/vc4_hdmi.c | 7 +++++--
  12  1 file changed, 5 insertions(+), 2 deletions(-)
  13
  14 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
  15 +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
  16 @@ -343,8 +343,11 @@ static void vc4_hdmi_encoder_mode_set(st
  17         csc_ctl = VC4_SET_FIELD(VC4_HD_CSC_CTL_ORDER_BGR,
  18                                 VC4_HD_CSC_CTL_ORDER);
  19
  20 -       if (vc4_encoder->hdmi_monitor && drm_match_cea_mode(mode) != 0) {
  21 -               /* Enable limited range RGB output.  This matrix is:
  22 +       if (vc4_encoder->hdmi_monitor && drm_match_cea_mode(mode) > 1) {
  23 +               /* CEA VICs other than #1 requre limited range RGB
  24 +                * output.  Apply a colorspace conversion to squash
  25 +                * 0-255 down to 16-235.  The matrix here is:
  26 +                *
  27                  * [ 0      0      0.8594 16]
  28                  * [ 0      0.8594 0      16]
  29                  * [ 0.8594 0      0      16]