| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <a13a968227214194b7033795a07ad554bfacfc8a.camel@mediatek.com>
Date: Wed, 10 Sep 2025 09:18:08 +0000
From: CK Hu (胡俊光) <ck.hu@...iatek.com>
To: "robh@...nel.org" <robh@...nel.org>, "krzk+dt@...nel.org"
<krzk+dt@...nel.org>, Paul-pl Chen (陳柏霖)
<Paul-pl.Chen@...iatek.com>, "conor+dt@...nel.org" <conor+dt@...nel.org>,
AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>,
"chunkuang.hu@...nel.org" <chunkuang.hu@...nel.org>
CC: Sunny Shen (沈姍姍) <Sunny.Shen@...iatek.com>,
Sirius Wang (王皓昱) <Sirius.Wang@...iatek.com>,
Nancy Lin (林欣螢) <Nancy.Lin@...iatek.com>,
Xiandong Wang (王先冬)
<Xiandong.Wang@...iatek.com>, "linux-kernel@...r.kernel.org"
<linux-kernel@...r.kernel.org>, "dri-devel@...ts.freedesktop.org"
<dri-devel@...ts.freedesktop.org>, Project_Global_Chrome_Upstream_Group
<Project_Global_Chrome_Upstream_Group@...iatek.com>,
"linux-mediatek@...ts.infradead.org" <linux-mediatek@...ts.infradead.org>,
Jason-JH Lin (林睿祥) <Jason-JH.Lin@...iatek.com>,
"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
"fshao@...omium.org" <fshao@...omium.org>, "p.zabel@...gutronix.de"
<p.zabel@...gutronix.de>, Singo Chang (張興國)
<Singo.Chang@...iatek.com>, "linux-arm-kernel@...ts.infradead.org"
<linux-arm-kernel@...ts.infradead.org>, "matthias.bgg@...il.com"
<matthias.bgg@...il.com>, "treapking@...omium.org" <treapking@...omium.org>
Subject: Re: [PATCH v4 13/19] drm/mediatek: Export OVL Blend function
On Thu, 2025-08-28 at 16:07 +0800, Paul Chen wrote:
> From: Paul-pl Chen <paul-pl.chen@...iatek.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@...iatek.com>
> Signed-off-by: Paul-pl Chen <paul-pl.chen@...iatek.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,
Powered by blists - more mailing lists