From 05202c241f1476d8e2b30bb2699f6780962972e8 Mon Sep 17 00:00:00 2001
From: Stefan Schake <stschake@gmail.com>
Date: Fri, 9 Mar 2018 01:53:34 +0100
Subject: [PATCH] drm/vc4: Set premultiplied for alpha formats
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(-)
diff --git a/drivers/gpu/drm/vc4/vc4_plane.c b/drivers/gpu/drm/vc4/vc4_plane.c
index c4c7af11fec5..831e1959e64d 100644
--- a/drivers/gpu/drm/vc4/vc4_plane.c
+++ b/drivers/gpu/drm/vc4/vc4_plane.c
@@ -618,13 +618,14 @@ static int vc4_plane_mode_set(struct drm_plane *plane,
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(fb->format->has_alpha ?
SCALER_POS2_ALPHA_MODE_PIPELINE :
SCALER_POS2_ALPHA_MODE_FIXED,
SCALER_POS2_ALPHA_MODE) |
+ (fb->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));
diff --git a/drivers/gpu/drm/vc4/vc4_regs.h b/drivers/gpu/drm/vc4/vc4_regs.h
index b9749cb24063..a141496104a6 100644
--- a/drivers/gpu/drm/vc4/vc4_regs.h
+++ b/drivers/gpu/drm/vc4/vc4_regs.h
@@ -848,6 +848,7 @@ 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