This addresses the following warning that appears at boot time:
--snip--
[PLANE:39:plane-0] pixel format with alpha exposed but blend mode not setup
WARNING: drivers/gpu/drm/drm_mode_config.c:872 at
drm_mode_config_validate+0x36c/0x520 [drm]
--snip--
The warning started appearing after the commit mentioned below was
introduced. Add the alpha and blending properties to the primary plane.
Fixes: 860e748bddcc ("drm: ensure blend mode supported if pixel format with
alpha exposed")
Signed-off-by: Laurentiu Palcu <[email protected]>
---
drivers/gpu/drm/imx/dcss/dcss-crtc.c | 6 ++++++
drivers/gpu/drm/imx/dcss/dcss-dev.h | 3 ++-
drivers/gpu/drm/imx/dcss/dcss-dtg.c | 12 ++++++++----
drivers/gpu/drm/imx/dcss/dcss-plane.c | 11 ++++++++++-
4 files changed, 26 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/imx/dcss/dcss-crtc.c
b/drivers/gpu/drm/imx/dcss/dcss-crtc.c
index ab41759a9f52d..8358219c94c0d 100644
--- a/drivers/gpu/drm/imx/dcss/dcss-crtc.c
+++ b/drivers/gpu/drm/imx/dcss/dcss-crtc.c
@@ -5,6 +5,7 @@
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
+#include <drm/drm_blend.h>
#include <drm/drm_vblank.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
@@ -202,6 +203,11 @@ int dcss_crtc_init(struct dcss_crtc *crtc, struct
drm_device *drm)
return ret;
}
+ drm_plane_create_alpha_property(&crtc->plane[0]->base);
+ drm_plane_create_blend_mode_property(&crtc->plane[0]->base,
+ BIT(DRM_MODE_BLEND_PIXEL_NONE) |
+ BIT(DRM_MODE_BLEND_COVERAGE));
+
crtc->irq = platform_get_irq_byname(pdev, "vblank");
if (crtc->irq < 0)
return crtc->irq;
diff --git a/drivers/gpu/drm/imx/dcss/dcss-dev.h
b/drivers/gpu/drm/imx/dcss/dcss-dev.h
index b032e873d227c..9b3bd2f3a7ef1 100644
--- a/drivers/gpu/drm/imx/dcss/dcss-dev.h
+++ b/drivers/gpu/drm/imx/dcss/dcss-dev.h
@@ -147,7 +147,8 @@ bool dcss_dtg_is_enabled(struct dcss_dtg *dtg);
void dcss_dtg_ctxld_kick_irq_enable(struct dcss_dtg *dtg, bool en);
bool dcss_dtg_global_alpha_changed(struct dcss_dtg *dtg, int ch_num, int
alpha);
void dcss_dtg_plane_alpha_set(struct dcss_dtg *dtg, int ch_num,
- const struct drm_format_info *format, int alpha);
+ const struct drm_format_info *format, int alpha,
+ unsigned int blend_mode);
void dcss_dtg_plane_pos_set(struct dcss_dtg *dtg, int ch_num,
int px, int py, int pw, int ph);
void dcss_dtg_ch_enable(struct dcss_dtg *dtg, int ch_num, bool en);
diff --git a/drivers/gpu/drm/imx/dcss/dcss-dtg.c
b/drivers/gpu/drm/imx/dcss/dcss-dtg.c
index 6bbfd9aa27aca..21da9d3cce4cb 100644
--- a/drivers/gpu/drm/imx/dcss/dcss-dtg.c
+++ b/drivers/gpu/drm/imx/dcss/dcss-dtg.c
@@ -3,6 +3,7 @@
* Copyright 2019 NXP.
*/
+#include <drm/drm_blend.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
@@ -268,17 +269,20 @@ bool dcss_dtg_global_alpha_changed(struct dcss_dtg *dtg,
int ch_num, int alpha)
}
void dcss_dtg_plane_alpha_set(struct dcss_dtg *dtg, int ch_num,
- const struct drm_format_info *format, int alpha)
+ const struct drm_format_info *format, int alpha,
+ unsigned int blend_mode)
{
/* we care about alpha only when channel 0 is concerned */
if (ch_num)
return;
/*
- * Use global alpha if pixel format does not have alpha channel or the
- * user explicitly chose to use global alpha (i.e. alpha is not OPAQUE).
+ * DCSS supports either global alpha or per-pixel blending, following
+ * the coverage blending formula (with global alpha set to opaque).
+ * When the pixel blend mode is PIXEL_NONE, the per-pixel alpha is
+ * meant to be ignored, so fall back to global alpha in that case too.
*/
- if (!format->has_alpha || alpha != 255)
+ if (!format->has_alpha || blend_mode == DRM_MODE_BLEND_PIXEL_NONE)
dtg->alpha_cfg = (alpha << DEFAULT_FG_ALPHA_POS) &
DEFAULT_FG_ALPHA_MASK;
else /* use per-pixel alpha otherwise */
dtg->alpha_cfg = CH1_ALPHA_SEL;
diff --git a/drivers/gpu/drm/imx/dcss/dcss-plane.c
b/drivers/gpu/drm/imx/dcss/dcss-plane.c
index 1746dc5d4b642..06413d0612349 100644
--- a/drivers/gpu/drm/imx/dcss/dcss-plane.c
+++ b/drivers/gpu/drm/imx/dcss/dcss-plane.c
@@ -209,6 +209,14 @@ static int dcss_plane_atomic_check(struct drm_plane *plane,
return -EINVAL;
}
+ /* DCSS supports either per-pixel or global alpha. Not both. */
+ if (new_plane_state->fb->format->has_alpha &&
+ new_plane_state->pixel_blend_mode != DRM_MODE_BLEND_PIXEL_NONE &&
+ new_plane_state->alpha != DRM_BLEND_ALPHA_OPAQUE) {
+ DRM_DEBUG_KMS("Both per-pixel and global alpha not
supported.\n");
+ return -EINVAL;
+ }
+
return 0;
}
@@ -336,7 +344,8 @@ static void dcss_plane_atomic_update(struct drm_plane
*plane,
dcss_dtg_plane_pos_set(dcss->dtg, dcss_plane->ch_num,
dst.x1, dst.y1, dst_w, dst_h);
dcss_dtg_plane_alpha_set(dcss->dtg, dcss_plane->ch_num,
- fb->format, new_state->alpha >> 8);
+ fb->format, new_state->alpha >> 8,
+ new_state->pixel_blend_mode);
if (!dcss_plane->ch_num && (new_state->alpha >> 8) == 0)
enable = false;
--
2.53.0
