target/linux/brcm2708/patches-4.14/950-0347-drm-vc4-Enable-background-color-fill-when-necessary.patch

   1 From 6510ecc6c76d040cc5a84f7464b5f327f2c556e9 Mon Sep 17 00:00:00 2001
   2 From: Stefan Schake <stschake@gmail.com>
   3 Date: Fri, 9 Mar 2018 01:53:37 +0100
   4 Subject: [PATCH 347/454] drm/vc4: Enable background color fill when necessary
   5
   6 commit 1d49f2e546a5a3258a88f85a1c04fd6feb6def37 upstream.
   7
   8 Using the hint from the plane state, we turn on the background color
   9 to avoid display corruption from planes blending with the background.
  10
  11 Changes from v1:
  12  - Use needs_bg_fill from plane state
  13
  14 Signed-off-by: Stefan Schake <stschake@gmail.com>
  15 Signed-off-by: Eric Anholt <eric@anholt.net>
  16 Reviewed-by: Eric Anholt <eric@anholt.net>
  17 Link: https://patchwork.freedesktop.org/patch/msgid/1520556817-97297-5-git-send-email-stschake@gmail.com
  18 ---
  19  drivers/gpu/drm/vc4/vc4_crtc.c | 25 +++++++++++++++++++++++++
  20  1 file changed, 25 insertions(+)
  21
  22 --- a/drivers/gpu/drm/vc4/vc4_crtc.c
  23 +++ b/drivers/gpu/drm/vc4/vc4_crtc.c
  24 @@ -646,9 +646,12 @@ static void vc4_crtc_atomic_flush(struct
  25  {
  26         struct drm_device *dev = crtc->dev;
  27         struct vc4_dev *vc4 = to_vc4_dev(dev);
  28 +       struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
  29         struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
  30         struct drm_plane *plane;
  31 +       struct vc4_plane_state *vc4_plane_state;
  32         bool debug_dump_regs = false;
  33 +       bool enable_bg_fill = false;
  34         u32 __iomem *dlist_start = vc4->hvs->dlist + vc4_state->mm.start;
  35         u32 __iomem *dlist_next = dlist_start;
  36
  37 @@ -659,6 +662,20 @@ static void vc4_crtc_atomic_flush(struct
  38
  39         /* Copy all the active planes' dlist contents to the hardware dlist. */
  40         drm_atomic_crtc_for_each_plane(plane, crtc) {
  41 +               /* Is this the first active plane? */
  42 +               if (dlist_next == dlist_start) {
  43 +                       /* We need to enable background fill when a plane
  44 +                        * could be alpha blending from the background, i.e.
  45 +                        * where no other plane is underneath. It suffices to
  46 +                        * consider the first active plane here since we set
  47 +                        * needs_bg_fill such that either the first plane
  48 +                        * already needs it or all planes on top blend from
  49 +                        * the first or a lower plane.
  50 +                        */
  51 +                       vc4_plane_state = to_vc4_plane_state(plane->state);
  52 +                       enable_bg_fill = vc4_plane_state->needs_bg_fill;
  53 +               }
  54 +
  55                 dlist_next += vc4_plane_write_dlist(plane, dlist_next);
  56         }
  57
  58 @@ -667,6 +684,14 @@ static void vc4_crtc_atomic_flush(struct
  59
  60         WARN_ON_ONCE(dlist_next - dlist_start != vc4_state->mm.size);
  61
  62 +       if (enable_bg_fill)
  63 +               /* This sets a black background color fill, as is the case
  64 +                * with other DRM drivers.
  65 +                */
  66 +               HVS_WRITE(SCALER_DISPBKGNDX(vc4_crtc->channel),
  67 +                         HVS_READ(SCALER_DISPBKGNDX(vc4_crtc->channel)) |
  68 +                         SCALER_DISPBKGND_FILL);
  69 +
  70         /* Only update DISPLIST if the CRTC was already running and is not
  71          * being disabled.
  72          * vc4_crtc_enable() takes care of updating the dlist just after