On 17/08/2021 20:48, abhinavk@xxxxxxxxxxxxxx wrote:
On 2021-06-28 12:19, Dmitry Baryshkov wrote:
Add support for alpha blending properties. Setup the plane blend state
according to those properties.
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
I think this has already been picked up by Rob but just had a couple of
comments
below.
Also, how has this been validated? On RB boards i dont think all the
paths get
executed.
I've used modetest to set pixel blending properties. The results looked
logical from my point of view.
---
drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 43 ++++++++++++++++-------
drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c | 10 ++++--
2 files changed, 37 insertions(+), 16 deletions(-)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
index 9a5c70c87cc8..768012243b44 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
@@ -30,12 +30,6 @@
#include "dpu_core_perf.h"
#include "dpu_trace.h"
-#define DPU_DRM_BLEND_OP_NOT_DEFINED 0
-#define DPU_DRM_BLEND_OP_OPAQUE 1
-#define DPU_DRM_BLEND_OP_PREMULTIPLIED 2
-#define DPU_DRM_BLEND_OP_COVERAGE 3
-#define DPU_DRM_BLEND_OP_MAX 4
-
/* layer mixer index on dpu_crtc */
#define LEFT_MIXER 0
#define RIGHT_MIXER 1
@@ -146,20 +140,43 @@ static void _dpu_crtc_setup_blend_cfg(struct
dpu_crtc_mixer *mixer,
{
struct dpu_hw_mixer *lm = mixer->hw_lm;
uint32_t blend_op;
+ uint32_t fg_alpha, bg_alpha;
- /* default to opaque blending */
- blend_op = DPU_BLEND_FG_ALPHA_FG_CONST |
- DPU_BLEND_BG_ALPHA_BG_CONST;
+ fg_alpha = pstate->base.alpha >> 8;
+ bg_alpha = 0xff - fg_alpha;
- if (format->alpha_enable) {
+ /* default to opaque blending */
+ if (pstate->base.pixel_blend_mode == DRM_MODE_BLEND_PIXEL_NONE ||
+ !format->alpha_enable) {
+ blend_op = DPU_BLEND_FG_ALPHA_FG_CONST |
+ DPU_BLEND_BG_ALPHA_BG_CONST;
+ } else if (pstate->base.pixel_blend_mode ==
DRM_MODE_BLEND_PREMULTI) {
+ blend_op = DPU_BLEND_FG_ALPHA_FG_CONST |
+ DPU_BLEND_BG_ALPHA_FG_PIXEL;
+ if (fg_alpha != 0xff) {
+ bg_alpha = fg_alpha;
+ blend_op |= DPU_BLEND_BG_MOD_ALPHA |
+ DPU_BLEND_BG_INV_MOD_ALPHA;
+ } else {
+ blend_op |= DPU_BLEND_BG_INV_ALPHA;
+ }
+ } else {
/* coverage blending */
blend_op = DPU_BLEND_FG_ALPHA_FG_PIXEL |
- DPU_BLEND_BG_ALPHA_FG_PIXEL |
- DPU_BLEND_BG_INV_ALPHA;
+ DPU_BLEND_BG_ALPHA_FG_PIXEL;
+ if (fg_alpha != 0xff) {
+ bg_alpha = fg_alpha;
+ blend_op |= DPU_BLEND_FG_MOD_ALPHA |
+ DPU_BLEND_FG_INV_MOD_ALPHA |
comparing this with the blend rule downstream, is this inversion necessary?
I only see below rule downstream:
628 if (fg_alpha != 0xff) {
629 bg_alpha = fg_alpha;
630 blend_op |= SDE_BLEND_FG_MOD_ALPHA |
631 SDE_BLEND_BG_MOD_ALPHA |
632 SDE_BLEND_BG_INV_MOD_ALPHA;
I've also stumbled upon this for quite some time. If you check old
kernel trees, you'll see that up to 4.9 there was an inversion. But
during the import to 4.14 this line was silently removed. I suspect that
it got lost because of some mistake during the import.
The same code (with the inversion) was present in the mdp5 driver.
Could you please check against the manual, how these bits should work?
See
https://www.kernel.org/doc/html/latest/gpu/drm-kms.html#plane-composition-properties
for the expected formulas.
+ DPU_BLEND_BG_MOD_ALPHA |
+ DPU_BLEND_BG_INV_MOD_ALPHA;
+ } else {
+ blend_op |= DPU_BLEND_BG_INV_ALPHA;
+ }
}
lm->ops.setup_blend_config(lm, pstate->stage,
- 0xFF, 0, blend_op);
+ fg_alpha, bg_alpha, blend_op);
DRM_DEBUG_ATOMIC("format:%p4cc, alpha_en:%u blend_op:0x%x\n",
&format->base.pixel_format, format->alpha_enable, blend_op);
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
index ec4a6f04394a..c989621209aa 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
@@ -1339,9 +1339,7 @@ static void dpu_plane_reset(struct drm_plane
*plane)
return;
}
- pstate->base.plane = plane;
-
- plane->state = &pstate->base;
+ __drm_atomic_helper_plane_reset(plane, &pstate->base);
}
#ifdef CONFIG_DEBUG_FS
@@ -1647,6 +1645,12 @@ struct drm_plane *dpu_plane_init(struct
drm_device *dev,
if (ret)
DPU_ERROR("failed to install zpos property, rc = %d\n", ret);
+ drm_plane_create_alpha_property(plane);
+ drm_plane_create_blend_mode_property(plane,
+ BIT(DRM_MODE_BLEND_PIXEL_NONE) |
+ BIT(DRM_MODE_BLEND_PREMULTI) |
+ BIT(DRM_MODE_BLEND_COVERAGE));
+
drm_plane_create_rotation_property(plane,
DRM_MODE_ROTATE_0,
DRM_MODE_ROTATE_0 |
--
With best wishes
Dmitry
