From 1d49f2e546a5a3258a88f85a1c04fd6feb6def37 Mon Sep 17 00:00:00 2001 From: Stefan Schake Date: Fri, 9 Mar 2018 01:53:37 +0100 Subject: [PATCH] drm/vc4: Enable background color fill when necessary 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 Signed-off-by: Eric Anholt Reviewed-by: Eric Anholt Link: https://patchwork.freedesktop.org/patch/msgid/1520556817-97297-5-git-send-email-stschake@gmail.com --- drivers/gpu/drm/vc4/vc4_crtc.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c index ce1e3b9..bf466748 100644 --- 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 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; + 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 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. + */ + 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 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 -- 2.7.4