target/linux/brcm2708/patches-4.14/950-0345-drm-vc4-Check-if-plane-requires-background-fill.patch

   1 From 7771310ee7e9b7291e549e36771de6176d57e24b Mon Sep 17 00:00:00 2001
   2 From: Stefan Schake <stschake@gmail.com>
   3 Date: Fri, 9 Mar 2018 01:53:35 +0100
   4 Subject: [PATCH 345/454] drm/vc4: Check if plane requires background fill
   5
   6 commit 3d67b68a6a3c2deb689c29759a20150c668c286e upstream.
   7
   8 Considering a single plane only, we have to enable background color
   9 when the plane has an alpha format and could be blending from the
  10 background or when it doesn't cover the entire screen.
  11
  12 Changes from v1:
  13  - Drop unrelated change
  14  - Move needs_bg_fill to plane state
  15
  16 Signed-off-by: Stefan Schake <stschake@gmail.com>
  17 Signed-off-by: Eric Anholt <eric@anholt.net>
  18 Reviewed-by: Eric Anholt <eric@anholt.net>
  19 Link: https://patchwork.freedesktop.org/patch/msgid/1520556817-97297-3-git-send-email-stschake@gmail.com
  20 ---
  21  drivers/gpu/drm/vc4/vc4_plane.c | 17 +++++++++++++++++
  22  1 file changed, 17 insertions(+)
  23
  24 --- a/drivers/gpu/drm/vc4/vc4_plane.c
  25 +++ b/drivers/gpu/drm/vc4/vc4_plane.c
  26 @@ -73,6 +73,12 @@ struct vc4_plane_state {
  27
  28         /* Our allocation in LBM for temporary storage during scaling. */
  29         struct drm_mm_node lbm;
  30 +
  31 +       /* Set when the plane has per-pixel alpha content or does not cover
  32 +        * the entire screen. This is a hint to the CRTC that it might need
  33 +        * to enable background color fill.
  34 +        */
  35 +       bool needs_bg_fill;
  36  };
  37
  38  static inline struct vc4_plane_state *
  39 @@ -522,6 +528,7 @@ static int vc4_plane_mode_set(struct drm
  40         u32 ctl0_offset = vc4_state->dlist_count;
  41         const struct hvs_format *format = vc4_get_hvs_format(fb->format->format);
  42         int num_planes = drm_format_num_planes(format->drm);
  43 +       bool covers_screen;
  44         u32 scl0, scl1, pitch0;
  45         u32 lbm_size, tiling;
  46         unsigned long irqflags;
  47 @@ -705,6 +712,16 @@ static int vc4_plane_mode_set(struct drm
  48         vc4_state->dlist[ctl0_offset] |=
  49                 VC4_SET_FIELD(vc4_state->dlist_count, SCALER_CTL0_SIZE);
  50
  51 +       /* crtc_* are already clipped coordinates. */
  52 +       covers_screen = vc4_state->crtc_x == 0 && vc4_state->crtc_y == 0 &&
  53 +                       vc4_state->crtc_w == state->crtc->mode.hdisplay &&
  54 +                       vc4_state->crtc_h == state->crtc->mode.vdisplay;
  55 +       /* Background fill might be necessary when the plane has per-pixel
  56 +        * alpha content and blends from the background or does not cover
  57 +        * the entire screen.
  58 +        */
  59 +       vc4_state->needs_bg_fill = format->has_alpha || !covers_screen;
  60 +
  61         return 0;
  62  }
  63