2022-01-03 05:47:17

by Miles Chen

[permalink] [raw]
Subject: [PATCH v4] drm/mediatek: Fix mtk_cec_mask()

In current implementation, mtk_cec_mask() writes val into target register
and ignores the mask. After talking to our hdmi experts, mtk_cec_mask()
should read a register, clean only mask bits, and update (val | mask) bits
to the register.

Fixes: 8f83f26891e1 ("drm/mediatek: Add HDMI support")

Cc: Zhiqiang Lin <[email protected]>
Cc: CK Hu <[email protected]>
Cc: Matthias Brugger <[email protected]>

Signed-off-by: Miles Chen <[email protected]>

---

Change since v1:
add Fixes tag

Change since v2:
add explanation of mtk_cec_mask()

Change since v3:
change misleading subject and modify the commit message since this is a bug fix patch

---
drivers/gpu/drm/mediatek/mtk_cec.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_cec.c b/drivers/gpu/drm/mediatek/mtk_cec.c
index e9cef5c0c8f7..cdfa648910b2 100644
--- a/drivers/gpu/drm/mediatek/mtk_cec.c
+++ b/drivers/gpu/drm/mediatek/mtk_cec.c
@@ -85,7 +85,7 @@ static void mtk_cec_mask(struct mtk_cec *cec, unsigned int offset,
u32 tmp = readl(cec->regs + offset) & ~mask;

tmp |= val & mask;
- writel(val, cec->regs + offset);
+ writel(tmp, cec->regs + offset);
}

void mtk_cec_set_hpd_event(struct device *dev,
--
2.18.0



2022-01-04 00:00:54

by Chun-Kuang Hu

[permalink] [raw]
Subject: Re: [PATCH v4] drm/mediatek: Fix mtk_cec_mask()

Hi, Miles:

Miles Chen <[email protected]> 於 2022年1月3日 週一 下午1:47寫道:
>
> In current implementation, mtk_cec_mask() writes val into target register
> and ignores the mask. After talking to our hdmi experts, mtk_cec_mask()
> should read a register, clean only mask bits, and update (val | mask) bits
> to the register.

Reviewed-by: Chun-Kuang Hu <[email protected]>

>
> Fixes: 8f83f26891e1 ("drm/mediatek: Add HDMI support")
>
> Cc: Zhiqiang Lin <[email protected]>
> Cc: CK Hu <[email protected]>
> Cc: Matthias Brugger <[email protected]>
>
> Signed-off-by: Miles Chen <[email protected]>
>
> ---
>
> Change since v1:
> add Fixes tag
>
> Change since v2:
> add explanation of mtk_cec_mask()
>
> Change since v3:
> change misleading subject and modify the commit message since this is a bug fix patch
>
> ---
> drivers/gpu/drm/mediatek/mtk_cec.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_cec.c b/drivers/gpu/drm/mediatek/mtk_cec.c
> index e9cef5c0c8f7..cdfa648910b2 100644
> --- a/drivers/gpu/drm/mediatek/mtk_cec.c
> +++ b/drivers/gpu/drm/mediatek/mtk_cec.c
> @@ -85,7 +85,7 @@ static void mtk_cec_mask(struct mtk_cec *cec, unsigned int offset,
> u32 tmp = readl(cec->regs + offset) & ~mask;
>
> tmp |= val & mask;
> - writel(val, cec->regs + offset);
> + writel(tmp, cec->regs + offset);
> }
>
> void mtk_cec_set_hpd_event(struct device *dev,
> --
> 2.18.0
>

Subject: Re: [PATCH v4] drm/mediatek: Fix mtk_cec_mask()

Il 03/01/22 06:47, Miles Chen ha scritto:
> In current implementation, mtk_cec_mask() writes val into target register
> and ignores the mask. After talking to our hdmi experts, mtk_cec_mask()
> should read a register, clean only mask bits, and update (val | mask) bits
> to the register.
>
> Fixes: 8f83f26891e1 ("drm/mediatek: Add HDMI support")
>
> Cc: Zhiqiang Lin <[email protected]>
> Cc: CK Hu <[email protected]>
> Cc: Matthias Brugger <[email protected]>
>
> Signed-off-by: Miles Chen <[email protected]>
> Reviewed-by: Chun-Kuang Hu <[email protected]>

Reviewed-by: AngeloGioacchino Del Regno <[email protected]>

> ---
>
> Change since v1:
> add Fixes tag
>
> Change since v2:
> add explanation of mtk_cec_mask()
>
> Change since v3:
> change misleading subject and modify the commit message since this is a bug fix patch
>
> ---
> drivers/gpu/drm/mediatek/mtk_cec.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_cec.c b/drivers/gpu/drm/mediatek/mtk_cec.c
> index e9cef5c0c8f7..cdfa648910b2 100644
> --- a/drivers/gpu/drm/mediatek/mtk_cec.c
> +++ b/drivers/gpu/drm/mediatek/mtk_cec.c
> @@ -85,7 +85,7 @@ static void mtk_cec_mask(struct mtk_cec *cec, unsigned int offset,
> u32 tmp = readl(cec->regs + offset) & ~mask;
>
> tmp |= val & mask;
> - writel(val, cec->regs + offset);
> + writel(tmp, cec->regs + offset);
> }
>
> void mtk_cec_set_hpd_event(struct device *dev,
>


2022-01-14 22:46:16

by Matthias Brugger

[permalink] [raw]
Subject: Re: [PATCH v4] drm/mediatek: Fix mtk_cec_mask()



On 03/01/2022 06:47, Miles Chen wrote:
> In current implementation, mtk_cec_mask() writes val into target register
> and ignores the mask. After talking to our hdmi experts, mtk_cec_mask()
> should read a register, clean only mask bits, and update (val | mask) bits
> to the register.
>
> Fixes: 8f83f26891e1 ("drm/mediatek: Add HDMI support")
>

Normally there is no new line here.

> Cc: Zhiqiang Lin <[email protected]>
> Cc: CK Hu <[email protected]>
> Cc: Matthias Brugger <[email protected]>
>

Neither here.

> Signed-off-by: Miles Chen <[email protected]>
>

But that are nit-picks. I leave it to the maintainer to decide if he want to fix
that when applying the patch:

Reviewed-by: Matthias Brugger <[email protected]>

Thanks a lot,
Matthias

> ---
>
> Change since v1:
> add Fixes tag
>
> Change since v2:
> add explanation of mtk_cec_mask()
>
> Change since v3:
> change misleading subject and modify the commit message since this is a bug fix patch
>
> ---
> drivers/gpu/drm/mediatek/mtk_cec.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_cec.c b/drivers/gpu/drm/mediatek/mtk_cec.c
> index e9cef5c0c8f7..cdfa648910b2 100644
> --- a/drivers/gpu/drm/mediatek/mtk_cec.c
> +++ b/drivers/gpu/drm/mediatek/mtk_cec.c
> @@ -85,7 +85,7 @@ static void mtk_cec_mask(struct mtk_cec *cec, unsigned int offset,
> u32 tmp = readl(cec->regs + offset) & ~mask;
>
> tmp |= val & mask;
> - writel(val, cec->regs + offset);
> + writel(tmp, cec->regs + offset);
> }
>
> void mtk_cec_set_hpd_event(struct device *dev,
>