From 3b196634f856b8cf6bd3c4777918c61fa054887e Mon Sep 17 00:00:00 2001
From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: Sun, 7 Mar 2021 02:56:58 +0200
Subject: drm: xlnx: zynqmp_dpsub: Fix graphics layer blending
Git-commit: e06926ecc3d04944ffc44069368d9fddf528413f
Patch-mainline: v5.15-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

To display the graphics layer, the global alpha needs to be enabled.
Enable it when the graphics plane is enabled (with full opacity), and
disable it otherwise.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/xlnx/zynqmp_disp.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xlnx/zynqmp_disp.c b/drivers/gpu/drm/xlnx/zynqmp_disp.c
index a061a75a9de7..27b3829fb7e0 100644
--- a/drivers/gpu/drm/xlnx/zynqmp_disp.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_disp.c
@@ -415,6 +415,11 @@ static void zynqmp_disp_avbuf_write(struct zynqmp_disp *disp, int reg, u32 val)
 	writel(val, disp->avbuf.base + reg);
 }
 
+static bool zynqmp_disp_layer_is_gfx(const struct zynqmp_disp_layer *layer)
+{
+	return layer->id == ZYNQMP_DISP_LAYER_GFX;
+}
+
 static bool zynqmp_disp_layer_is_video(const struct zynqmp_disp_layer *layer)
 {
 	return layer->id == ZYNQMP_DISP_LAYER_VID;
@@ -1157,6 +1162,9 @@ zynqmp_disp_plane_atomic_disable(struct drm_plane *plane,
 		return;
 
 	zynqmp_disp_layer_disable(layer);
+
+	if (zynqmp_disp_layer_is_gfx(layer))
+		zynqmp_disp_blend_set_global_alpha(layer->disp, false, 0);
 }
 
 static void
@@ -1186,6 +1194,9 @@ zynqmp_disp_plane_atomic_update(struct drm_plane *plane,
 
 	zynqmp_disp_layer_update(layer, new_state);
 
+	if (zynqmp_disp_layer_is_gfx(layer))
+		zynqmp_disp_blend_set_global_alpha(layer->disp, true, 255);
+
 	/* Enable or re-enable the plane is the format has changed. */
 	if (format_changed)
 		zynqmp_disp_layer_enable(layer);
@@ -1447,7 +1458,6 @@ zynqmp_disp_crtc_atomic_enable(struct drm_crtc *crtc,
 
 	zynqmp_disp_blend_set_output_format(disp, ZYNQMP_DPSUB_FORMAT_RGB);
 	zynqmp_disp_blend_set_bg_color(disp, 0, 0, 0);
-	zynqmp_disp_blend_set_global_alpha(disp, false, 0);
 
 	zynqmp_disp_enable(disp);
 
-- 
2.38.1