From 641b88e2572a66be56c2c1d5aae9acd38d8c6932 Mon Sep 17 00:00:00 2001
From: Stefan Schake <stschake@gmail.com>
Date: Fri, 9 Mar 2018 01:53:34 +0100
Subject: [PATCH 344/454] drm/vc4: Set premultiplied for alpha formats

commit 05202c241f1476d8e2b30bb2699f6780962972e8 upstream.

Alpha formats in DRM are assumed to be premultiplied, so we should be
setting the PREMULT bit in the plane configuration for HVS.

Changes from v1:
 - Use correct has_alpha

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/1520556817-97297-2-git-send-email-stschake@gmail.com
---
 drivers/gpu/drm/vc4/vc4_plane.c | 3 ++-
 drivers/gpu/drm/vc4/vc4_regs.h  | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/vc4/vc4_plane.c
+++ b/drivers/gpu/drm/vc4/vc4_plane.c
@@ -621,13 +621,14 @@ static int vc4_plane_mode_set(struct drm
 					      SCALER_POS1_SCL_HEIGHT));
 	}
 
-	/* Position Word 2: Source Image Size, Alpha Mode */
+	/* Position Word 2: Source Image Size, Alpha */
 	vc4_state->pos2_offset = vc4_state->dlist_count;
 	vc4_dlist_write(vc4_state,
 			VC4_SET_FIELD(format->has_alpha ?
 				      SCALER_POS2_ALPHA_MODE_PIPELINE :
 				      SCALER_POS2_ALPHA_MODE_FIXED,
 				      SCALER_POS2_ALPHA_MODE) |
+			(format->has_alpha ? SCALER_POS2_ALPHA_PREMULT : 0) |
 			VC4_SET_FIELD(vc4_state->src_w[0], SCALER_POS2_WIDTH) |
 			VC4_SET_FIELD(vc4_state->src_h[0], SCALER_POS2_HEIGHT));
 
--- a/drivers/gpu/drm/vc4/vc4_regs.h
+++ b/drivers/gpu/drm/vc4/vc4_regs.h
@@ -877,6 +877,7 @@ enum hvs_pixel_format {
 #define SCALER_POS2_ALPHA_MODE_FIXED		1
 #define SCALER_POS2_ALPHA_MODE_FIXED_NONZERO	2
 #define SCALER_POS2_ALPHA_MODE_FIXED_OVER_0x07	3
+#define SCALER_POS2_ALPHA_PREMULT		BIT(29)
 
 #define SCALER_POS2_HEIGHT_MASK			VC4_MASK(27, 16)
 #define SCALER_POS2_HEIGHT_SHIFT		16
