From: Stefan Schake <stschake@gmail.com>
Date: Fri, 9 Mar 2018 01:53:37 +0100
Subject: drm/vc4: Enable background color fill when necessary
Git-commit: 1d49f2e546a5a3258a88f85a1c04fd6feb6def37
Patch-mainline: v4.17-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
Using the hint from the plane state, we turn on the background color
to avoid display corruption from planes blending with the background.
Changes from v1:
- Use needs_bg_fill from plane state
Signed-off-by: Stefan Schake <stschake@gmail.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/1520556817-97297-5-git-send-email-stschake@gmail.com
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/vc4/vc4_crtc.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -643,9 +643,12 @@ static void vc4_crtc_atomic_flush(struct
{
struct drm_device *dev = crtc->dev;
struct vc4_dev *vc4 = to_vc4_dev(dev);
+ struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
struct drm_plane *plane;
+ struct vc4_plane_state *vc4_plane_state;
bool debug_dump_regs = false;
+ bool enable_bg_fill = false;
u32 __iomem *dlist_start = vc4->hvs->dlist + vc4_state->mm.start;
u32 __iomem *dlist_next = dlist_start;
@@ -656,6 +659,20 @@ static void vc4_crtc_atomic_flush(struct
/* Copy all the active planes' dlist contents to the hardware dlist. */
drm_atomic_crtc_for_each_plane(plane, crtc) {
+ /* Is this the first active plane? */
+ if (dlist_next == dlist_start) {
+ /* We need to enable background fill when a plane
+ * could be alpha blending from the background, i.e.
+ * where no other plane is underneath. It suffices to
+ * consider the first active plane here since we set
+ * needs_bg_fill such that either the first plane
+ * already needs it or all planes on top blend from
+ * the first or a lower plane.
+ */
+ vc4_plane_state = to_vc4_plane_state(plane->state);
+ enable_bg_fill = vc4_plane_state->needs_bg_fill;
+ }
+
dlist_next += vc4_plane_write_dlist(plane, dlist_next);
}
@@ -664,6 +681,14 @@ static void vc4_crtc_atomic_flush(struct
WARN_ON_ONCE(dlist_next - dlist_start != vc4_state->mm.size);
+ if (enable_bg_fill)
+ /* This sets a black background color fill, as is the case
+ * with other DRM drivers.
+ */
+ HVS_WRITE(SCALER_DISPBKGNDX(vc4_crtc->channel),
+ HVS_READ(SCALER_DISPBKGNDX(vc4_crtc->channel)) |
+ SCALER_DISPBKGND_FILL);
+
/* Only update DISPLIST if the CRTC was already running and is not
* being disabled.
* vc4_crtc_enable() takes care of updating the dlist just after