target/linux/bcm27xx/patches-5.15/950-0572-drm-vc4-Don-t-try-disabling-SCDC-on-Pi0-3.patch

   1 From e1ee82fdfdba0b210974cf3ccc0048c5aeb83bc6 Mon Sep 17 00:00:00 2001
   2 From: Dave Stevenson <dave.stevenson@raspberrypi.com>
   3 Date: Tue, 16 Nov 2021 10:34:34 +0000
   4 Subject: [PATCH] drm/vc4: Don't try disabling SCDC on Pi0-3.
   5
   6 The code that set the scdc_enabled flag to ensure it was
   7 disabled at boot time also ran on Pi0-3 where there is no
   8 SCDC support. This lead to a warning in vc4_hdmi_encoder_post_crtc_disable
   9 due to vc4_hdmi_disable_scrambling being called and trying to
  10 read (and write) register HDMI_SCRAMBLER_CTL which doesn't
  11 exist on those platforms.
  12
  13 Only set the flag should the interface be configured to support
  14 more than HDMI 1.4.
  15
  16 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
  17 ---
  18  drivers/gpu/drm/vc4/vc4_hdmi.c | 3 ++-
  19  1 file changed, 2 insertions(+), 1 deletion(-)
  20
  21 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
  22 +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
  23 @@ -2557,7 +2557,8 @@ static int vc4_hdmi_bind(struct device *
  24          * vc4_hdmi_disable_scrambling() will thus run at boot, make
  25          * sure it's disabled, and avoid any inconsistency.
  26          */
  27 -       vc4_hdmi->scdc_enabled = true;
  28 +       if (variant->max_pixel_clock > HDMI_14_MAX_TMDS_CLK)
  29 +               vc4_hdmi->scdc_enabled = true;
  30
  31         ret = variant->init_resources(vc4_hdmi);
  32         if (ret)