Using the hint from the plane state, we turn on the background color to avoid display corruption from planes blending with the background.
Signed-off-by: Stefan Schake stschake@gmail.com --- drivers/gpu/drm/vc4/vc4_crtc.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)
diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c index ce1e3b9..728845f 100644 --- a/drivers/gpu/drm/vc4/vc4_crtc.c +++ b/drivers/gpu/drm/vc4/vc4_crtc.c @@ -643,9 +643,11 @@ static void vc4_crtc_atomic_flush(struct drm_crtc *crtc, { 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; 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 +658,18 @@ static void vc4_crtc_atomic_flush(struct drm_crtc *crtc,
/* 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. + */ + enable_bg_fill = to_vc4_plane(plane)->needs_bg_fill; + dlist_next += vc4_plane_write_dlist(plane, dlist_next); }
@@ -664,6 +678,14 @@ static void vc4_crtc_atomic_flush(struct drm_crtc *crtc,
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