From: Paul-pl Chen <paul-pl.chen@mediatek.com>
For the new BLENDER component, the OVL ignore pixel alpha logic
should be exported as a function and reused it.
Signed-off-by: Nancy Lin <nancy.lin@mediatek.com>
Signed-off-by: Paul-pl Chen <paul-pl.chen@mediatek.com>
---
drivers/gpu/drm/mediatek/mtk_disp_ovl.c | 68 +++++++++++++++++--------
drivers/gpu/drm/mediatek/mtk_disp_ovl.h | 8 +++
2 files changed, 56 insertions(+), 20 deletions(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
index e3ee3f60f4ba..7cd3978beb98 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
@@ -228,6 +228,23 @@ void mtk_ovl_disable_vblank(struct device *dev)
writel_relaxed(0x0, ovl->regs + DISP_REG_OVL_INTEN);
}
+bool mtk_ovl_is_ignore_pixel_alpha(struct mtk_plane_state *state, unsigned int blend_mode)
+{
+ if (!state->base.fb)
+ return false;
+
+ /*
+ * Although the alpha channel can be ignored, CONST_BLD must be enabled
+ * for XRGB format, otherwise OVL will still read the value from memory.
+ * For RGB888 related formats, whether CONST_BLD is enabled or not won't
+ * affect the result. Therefore we use !has_alpha as the condition.
+ */
+ if (blend_mode == DRM_MODE_BLEND_PIXEL_NONE || !state->base.fb->format->has_alpha)
+ return true;
+
+ return false;
+}
+
u32 mtk_ovl_get_blend_modes(struct device *dev)
{
struct mtk_disp_ovl *ovl = dev_get_drvdata(dev);
@@ -414,6 +431,29 @@ void mtk_ovl_layer_off(struct device *dev, unsigned int idx,
DISP_REG_OVL_RDMA_CTRL(idx));
}
+unsigned int mtk_ovl_get_blend_mode(struct mtk_plane_state *state, unsigned int blend_modes)
+{
+ unsigned int blend_mode = DRM_MODE_BLEND_COVERAGE;
+
+ /*
+ * For the platforms where OVL_CON_CLRFMT_MAN is defined in the hardware data sheet
+ * and supports premultiplied color formats, such as OVL_CON_CLRFMT_PARGB888
+ * and supports premultiplied color formats, such as OVL_CON_CLRFMT_PARGB8888.
+ *
+ * Check blend_modes in the driver data to see if premultiplied mode is supported.
+ * If not, use coverage mode instead to set it to the supported color formats.
+ *
+ * Current DRM assumption is that alpha is default premultiplied, so the bitmask of
+ * blend_modes must include BIT(DRM_MODE_BLEND_PREMULTI). Otherwise, mtk_plane_init()
+ * will get an error return from drm_plane_create_blend_mode_property() and
+ * state->base.pixel_blend_mode should not be used.
+ */
+ if (blend_modes & BIT(DRM_MODE_BLEND_PREMULTI))
+ blend_mode = state->base.pixel_blend_mode;
+
+ return blend_mode;
+}
+
unsigned int mtk_ovl_fmt_convert(unsigned int fmt, unsigned int blend_mode,
bool fmt_rgb565_is_0, bool color_convert,
u8 clrfmt_shift, u32 clrfmt_man, u32 byte_swap, u32 rgb_swap)
@@ -541,7 +581,7 @@ void mtk_ovl_layer_config(struct device *dev, unsigned int idx,
unsigned int rotation = pending->rotation;
unsigned int offset = (pending->y << 16) | pending->x;
unsigned int src_size = (pending->height << 16) | pending->width;
- unsigned int blend_mode = state->base.pixel_blend_mode;
+ unsigned int blend_mode = mtk_ovl_get_blend_mode(state, ovl->data->blend_modes);
unsigned int ignore_pixel_alpha = 0;
unsigned int con;
@@ -566,17 +606,8 @@ void mtk_ovl_layer_config(struct device *dev, unsigned int idx,
* For blend_modes supported SoCs, always enable alpha blending.
* For blend_modes unsupported SoCs, enable alpha blending when has_alpha is set.
*/
- if (blend_mode || state->base.fb->format->has_alpha)
+ if (state->base.pixel_blend_mode || state->base.fb->format->has_alpha)
con |= OVL_CON_AEN;
-
- /*
- * Although the alpha channel can be ignored, CONST_BLD must be enabled
- * for XRGB format, otherwise OVL will still read the value from memory.
- * For RGB888 related formats, whether CONST_BLD is enabled or not won't
- * affect the result. Therefore we use !has_alpha as the condition.
- */
- if (blend_mode == DRM_MODE_BLEND_PIXEL_NONE || !state->base.fb->format->has_alpha)
- ignore_pixel_alpha = OVL_CONST_BLEND;
}
/*
@@ -602,6 +633,9 @@ void mtk_ovl_layer_config(struct device *dev, unsigned int idx,
mtk_ddp_write_relaxed(cmdq_pkt, con, &ovl->cmdq_reg, ovl->regs,
DISP_REG_OVL_CON(idx));
+
+ if (mtk_ovl_is_ignore_pixel_alpha(state, blend_mode))
+ ignore_pixel_alpha = OVL_CONST_BLEND;
mtk_ddp_write_relaxed(cmdq_pkt, pitch_lsb | ignore_pixel_alpha,
&ovl->cmdq_reg, ovl->regs, DISP_REG_OVL_PITCH(idx));
mtk_ddp_write_relaxed(cmdq_pkt, src_size, &ovl->cmdq_reg, ovl->regs,
@@ -751,9 +785,7 @@ static const struct mtk_disp_ovl_data mt8192_ovl_driver_data = {
.layer_nr = 4,
.fmt_rgb565_is_0 = true,
.smi_id_en = true,
- .blend_modes = BIT(DRM_MODE_BLEND_PREMULTI) |
- BIT(DRM_MODE_BLEND_COVERAGE) |
- BIT(DRM_MODE_BLEND_PIXEL_NONE),
+ .blend_modes = MTK_OVL_SUPPORT_BLEND_MODES,
.formats = mt8173_ovl_formats,
.num_formats = mt8173_ovl_formats_len,
};
@@ -764,9 +796,7 @@ static const struct mtk_disp_ovl_data mt8192_ovl_2l_driver_data = {
.layer_nr = 2,
.fmt_rgb565_is_0 = true,
.smi_id_en = true,
- .blend_modes = BIT(DRM_MODE_BLEND_PREMULTI) |
- BIT(DRM_MODE_BLEND_COVERAGE) |
- BIT(DRM_MODE_BLEND_PIXEL_NONE),
+ .blend_modes = MTK_OVL_SUPPORT_BLEND_MODES,
.formats = mt8173_ovl_formats,
.num_formats = mt8173_ovl_formats_len,
};
@@ -778,9 +808,7 @@ static const struct mtk_disp_ovl_data mt8195_ovl_driver_data = {
.fmt_rgb565_is_0 = true,
.smi_id_en = true,
.supports_afbc = true,
- .blend_modes = BIT(DRM_MODE_BLEND_PREMULTI) |
- BIT(DRM_MODE_BLEND_COVERAGE) |
- BIT(DRM_MODE_BLEND_PIXEL_NONE),
+ .blend_modes = MTK_OVL_SUPPORT_BLEND_MODES,
.formats = mt8195_ovl_formats,
.num_formats = mt8195_ovl_formats_len,
.supports_clrfmt_ext = true,
diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl.h b/drivers/gpu/drm/mediatek/mtk_disp_ovl.h
index 4f446d2e0712..431567538eb5 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_ovl.h
+++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl.h
@@ -6,14 +6,22 @@
#ifndef __MTK_DISP_OVL_H__
#define __MTK_DISP_OVL_H__
+#include <drm/drm_blend.h>
#include <drm/drm_fourcc.h>
+#define MTK_OVL_SUPPORT_BLEND_MODES \
+ (BIT(DRM_MODE_BLEND_PREMULTI) | \
+ BIT(DRM_MODE_BLEND_COVERAGE) | \
+ BIT(DRM_MODE_BLEND_PIXEL_NONE))
+
extern const u32 mt8173_ovl_formats[];
extern const size_t mt8173_ovl_formats_len;
extern const u32 mt8195_ovl_formats[];
extern const size_t mt8195_ovl_formats_len;
bool mtk_ovl_is_10bit_rgb(unsigned int fmt);
+bool mtk_ovl_is_ignore_pixel_alpha(struct mtk_plane_state *state, unsigned int blend_mode);
+unsigned int mtk_ovl_get_blend_mode(struct mtk_plane_state *state, unsigned int blend_modes);
unsigned int mtk_ovl_fmt_convert(unsigned int fmt, unsigned int blend_mode,
bool fmt_rgb565_is_0, bool color_convert,
u8 clrfmt_shift, u32 clrfmt_man, u32 byte_swap, u32 rgb_swap);
--
2.45.2On Thu, 2025-08-28 at 16:07 +0800, Paul Chen wrote:
> From: Paul-pl Chen <paul-pl.chen@mediatek.com>
>
> For the new BLENDER component, the OVL ignore pixel alpha logic
> should be exported as a function and reused it.
>
> Signed-off-by: Nancy Lin <nancy.lin@mediatek.com>
> Signed-off-by: Paul-pl Chen <paul-pl.chen@mediatek.com>
> ---
> drivers/gpu/drm/mediatek/mtk_disp_ovl.c | 68 +++++++++++++++++--------
> drivers/gpu/drm/mediatek/mtk_disp_ovl.h | 8 +++
> 2 files changed, 56 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> index e3ee3f60f4ba..7cd3978beb98 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> @@ -228,6 +228,23 @@ void mtk_ovl_disable_vblank(struct device *dev)
> writel_relaxed(0x0, ovl->regs + DISP_REG_OVL_INTEN);
> }
>
> +bool mtk_ovl_is_ignore_pixel_alpha(struct mtk_plane_state *state, unsigned int blend_mode)
> +{
> + if (!state->base.fb)
> + return false;
> +
> + /*
> + * Although the alpha channel can be ignored, CONST_BLD must be enabled
> + * for XRGB format, otherwise OVL will still read the value from memory.
> + * For RGB888 related formats, whether CONST_BLD is enabled or not won't
> + * affect the result. Therefore we use !has_alpha as the condition.
> + */
> + if (blend_mode == DRM_MODE_BLEND_PIXEL_NONE || !state->base.fb->format->has_alpha)
> + return true;
> +
> + return false;
> +}
> +
> u32 mtk_ovl_get_blend_modes(struct device *dev)
> {
> struct mtk_disp_ovl *ovl = dev_get_drvdata(dev);
> @@ -414,6 +431,29 @@ void mtk_ovl_layer_off(struct device *dev, unsigned int idx,
> DISP_REG_OVL_RDMA_CTRL(idx));
> }
>
> +unsigned int mtk_ovl_get_blend_mode(struct mtk_plane_state *state, unsigned int blend_modes)
> +{
> + unsigned int blend_mode = DRM_MODE_BLEND_COVERAGE;
> +
> + /*
> + * For the platforms where OVL_CON_CLRFMT_MAN is defined in the hardware data sheet
> + * and supports premultiplied color formats, such as OVL_CON_CLRFMT_PARGB888
> + * and supports premultiplied color formats, such as OVL_CON_CLRFMT_PARGB8888.
> + *
> + * Check blend_modes in the driver data to see if premultiplied mode is supported.
> + * If not, use coverage mode instead to set it to the supported color formats.
> + *
> + * Current DRM assumption is that alpha is default premultiplied, so the bitmask of
> + * blend_modes must include BIT(DRM_MODE_BLEND_PREMULTI). Otherwise, mtk_plane_init()
> + * will get an error return from drm_plane_create_blend_mode_property() and
> + * state->base.pixel_blend_mode should not be used.
> + */
> + if (blend_modes & BIT(DRM_MODE_BLEND_PREMULTI))
> + blend_mode = state->base.pixel_blend_mode;
> +
> + return blend_mode;
> +}
> +
> unsigned int mtk_ovl_fmt_convert(unsigned int fmt, unsigned int blend_mode,
> bool fmt_rgb565_is_0, bool color_convert,
> u8 clrfmt_shift, u32 clrfmt_man, u32 byte_swap, u32 rgb_swap)
> @@ -541,7 +581,7 @@ void mtk_ovl_layer_config(struct device *dev, unsigned int idx,
> unsigned int rotation = pending->rotation;
> unsigned int offset = (pending->y << 16) | pending->x;
> unsigned int src_size = (pending->height << 16) | pending->width;
> - unsigned int blend_mode = state->base.pixel_blend_mode;
> + unsigned int blend_mode = mtk_ovl_get_blend_mode(state, ovl->data->blend_modes);
Why you change behavior here?
Originally, 'blend_mode = state->base.pixel_blend_mode' directly.
But this patch add a check and blend_mode may be DRM_MODE_BLEND_COVERAGE.
The behavior changes. Why change this behavior?
> unsigned int ignore_pixel_alpha = 0;
> unsigned int con;
>
> @@ -566,17 +606,8 @@ void mtk_ovl_layer_config(struct device *dev, unsigned int idx,
> * For blend_modes supported SoCs, always enable alpha blending.
> * For blend_modes unsupported SoCs, enable alpha blending when has_alpha is set.
> */
> - if (blend_mode || state->base.fb->format->has_alpha)
> + if (state->base.pixel_blend_mode || state->base.fb->format->has_alpha)
> con |= OVL_CON_AEN;
> -
> - /*
> - * Although the alpha channel can be ignored, CONST_BLD must be enabled
> - * for XRGB format, otherwise OVL will still read the value from memory.
> - * For RGB888 related formats, whether CONST_BLD is enabled or not won't
> - * affect the result. Therefore we use !has_alpha as the condition.
> - */
> - if (blend_mode == DRM_MODE_BLEND_PIXEL_NONE || !state->base.fb->format->has_alpha)
> - ignore_pixel_alpha = OVL_CONST_BLEND;
> }
>
> /*
> @@ -602,6 +633,9 @@ void mtk_ovl_layer_config(struct device *dev, unsigned int idx,
>
> mtk_ddp_write_relaxed(cmdq_pkt, con, &ovl->cmdq_reg, ovl->regs,
> DISP_REG_OVL_CON(idx));
> +
> + if (mtk_ovl_is_ignore_pixel_alpha(state, blend_mode))
> + ignore_pixel_alpha = OVL_CONST_BLEND;
> mtk_ddp_write_relaxed(cmdq_pkt, pitch_lsb | ignore_pixel_alpha,
> &ovl->cmdq_reg, ovl->regs, DISP_REG_OVL_PITCH(idx));
> mtk_ddp_write_relaxed(cmdq_pkt, src_size, &ovl->cmdq_reg, ovl->regs,
On Wed, 2025-09-10 at 09:18 +0000, CK Hu (胡俊光) wrote:
> On Thu, 2025-08-28 at 16:07 +0800, Paul Chen wrote:
> > From: Paul-pl Chen <paul-pl.chen@mediatek.com>
> >
> > For the new BLENDER component, the OVL ignore pixel alpha logic
> > should be exported as a function and reused it.
> >
> > Signed-off-by: Nancy Lin <nancy.lin@mediatek.com>
> > Signed-off-by: Paul-pl Chen <paul-pl.chen@mediatek.com>
> > ---
> > drivers/gpu/drm/mediatek/mtk_disp_ovl.c | 68 +++++++++++++++++----
> > ----
> > drivers/gpu/drm/mediatek/mtk_disp_ovl.h | 8 +++
> > 2 files changed, 56 insertions(+), 20 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> > b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> > index e3ee3f60f4ba..7cd3978beb98 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
> > @@ -228,6 +228,23 @@ void mtk_ovl_disable_vblank(struct device
> > *dev)
> > writel_relaxed(0x0, ovl->regs + DISP_REG_OVL_INTEN);
> > }
> >
> > +bool mtk_ovl_is_ignore_pixel_alpha(struct mtk_plane_state *state,
> > unsigned int blend_mode)
> > +{
> > + if (!state->base.fb)
> > + return false;
> > +
> > + /*
> > + * Although the alpha channel can be ignored, CONST_BLD
> > must be enabled
> > + * for XRGB format, otherwise OVL will still read the
> > value from memory.
> > + * For RGB888 related formats, whether CONST_BLD is
> > enabled or not won't
> > + * affect the result. Therefore we use !has_alpha as the
> > condition.
> > + */
> > + if (blend_mode == DRM_MODE_BLEND_PIXEL_NONE || !state-
> > >base.fb->format->has_alpha)
> > + return true;
> > +
> > + return false;
> > +}
> > +
> > u32 mtk_ovl_get_blend_modes(struct device *dev)
> > {
> > struct mtk_disp_ovl *ovl = dev_get_drvdata(dev);
> > @@ -414,6 +431,29 @@ void mtk_ovl_layer_off(struct device *dev,
> > unsigned int idx,
> > DISP_REG_OVL_RDMA_CTRL(idx));
> > }
> >
> > +unsigned int mtk_ovl_get_blend_mode(struct mtk_plane_state *state,
> > unsigned int blend_modes)
> > +{
> > + unsigned int blend_mode = DRM_MODE_BLEND_COVERAGE;
> > +
> > + /*
> > + * For the platforms where OVL_CON_CLRFMT_MAN is defined
> > in the hardware data sheet
> > + * and supports premultiplied color formats, such as
> > OVL_CON_CLRFMT_PARGB888
> > + * and supports premultiplied color formats, such as
> > OVL_CON_CLRFMT_PARGB8888.
> > + *
> > + * Check blend_modes in the driver data to see if
> > premultiplied mode is supported.
> > + * If not, use coverage mode instead to set it to the
> > supported color formats.
> > + *
> > + * Current DRM assumption is that alpha is default
> > premultiplied, so the bitmask of
> > + * blend_modes must include BIT(DRM_MODE_BLEND_PREMULTI).
> > Otherwise, mtk_plane_init()
> > + * will get an error return from
> > drm_plane_create_blend_mode_property() and
> > + * state->base.pixel_blend_mode should not be used.
> > + */
> > + if (blend_modes & BIT(DRM_MODE_BLEND_PREMULTI))
> > + blend_mode = state->base.pixel_blend_mode;
> > +
> > + return blend_mode;
> > +}
> > +
> > unsigned int mtk_ovl_fmt_convert(unsigned int fmt, unsigned int
> > blend_mode,
> > bool fmt_rgb565_is_0, bool
> > color_convert,
> > u8 clrfmt_shift, u32 clrfmt_man,
> > u32 byte_swap, u32 rgb_swap)
> > @@ -541,7 +581,7 @@ void mtk_ovl_layer_config(struct device *dev,
> > unsigned int idx,
> > unsigned int rotation = pending->rotation;
> > unsigned int offset = (pending->y << 16) | pending->x;
> > unsigned int src_size = (pending->height << 16) | pending-
> > >width;
> > - unsigned int blend_mode = state->base.pixel_blend_mode;
> > + unsigned int blend_mode = mtk_ovl_get_blend_mode(state,
> > ovl->data->blend_modes);
>
> Why you change behavior here?
> Originally, 'blend_mode = state->base.pixel_blend_mode' directly.
> But this patch add a check and blend_mode may be
> DRM_MODE_BLEND_COVERAGE.
> The behavior changes. Why change this behavior?
>
It's for convenient to optimize the logic design.
> > unsigned int ignore_pixel_alpha = 0;
> > unsigned int con;
> >
> > @@ -566,17 +606,8 @@ void mtk_ovl_layer_config(struct device *dev,
> > unsigned int idx,
> > * For blend_modes supported SoCs, always enable
> > alpha blending.
> > * For blend_modes unsupported SoCs, enable alpha
> > blending when has_alpha is set.
> > */
> > - if (blend_mode || state->base.fb->format-
> > >has_alpha)
> > + if (state->base.pixel_blend_mode || state-
> > >base.fb->format->has_alpha)
> > con |= OVL_CON_AEN;
> > -
> > - /*
> > - * Although the alpha channel can be ignored,
> > CONST_BLD must be enabled
> > - * for XRGB format, otherwise OVL will still read
> > the value from memory.
> > - * For RGB888 related formats, whether CONST_BLD
> > is enabled or not won't
> > - * affect the result. Therefore we use !has_alpha
> > as the condition.
> > - */
> > - if (blend_mode == DRM_MODE_BLEND_PIXEL_NONE ||
> > !state->base.fb->format->has_alpha)
> > - ignore_pixel_alpha = OVL_CONST_BLEND;
> > }
> >
> > /*
> > @@ -602,6 +633,9 @@ void mtk_ovl_layer_config(struct device *dev,
> > unsigned int idx,
> >
> > mtk_ddp_write_relaxed(cmdq_pkt, con, &ovl->cmdq_reg, ovl-
> > >regs,
> > DISP_REG_OVL_CON(idx));
> > +
> > + if (mtk_ovl_is_ignore_pixel_alpha(state, blend_mode))
> > + ignore_pixel_alpha = OVL_CONST_BLEND;
> > mtk_ddp_write_relaxed(cmdq_pkt, pitch_lsb |
> > ignore_pixel_alpha,
> > &ovl->cmdq_reg, ovl->regs,
> > DISP_REG_OVL_PITCH(idx));
> > mtk_ddp_write_relaxed(cmdq_pkt, src_size, &ovl->cmdq_reg,
> > ovl->regs,
>
© 2016 - 2026 Red Hat, Inc.