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

From: CK Hu
Date: Wed Apr 06 2022 - 21:31:58 EST


Hi, Miles:

On Wed, 2022-03-16 at 07:23 +0800, 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.

Applied to mediatek-drm-next [1], thanks.

[1]
https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?h=mediatek-drm-next

Regards,
CK

>
> Fixes: 8f83f26891e1 ("drm/mediatek: Add HDMI support")
> Signed-off-by: Miles Chen <miles.chen@xxxxxxxxxxxx>
> Reviewed-by: Chun-Kuang Hu <chunkuang.hu@xxxxxxxxxx>
> Reviewed-by: AngeloGioacchino Del Regno <
> angelogioacchino.delregno@xxxxxxxxxxxxx>
> Reviewed-by: Matthias Brugger <matthias.bgg@xxxxxxxxx>
> Cc: Zhiqiang Lin <zhiqiang.lin@xxxxxxxxxxxx>
> Cc: CK Hu <ck.hu@xxxxxxxxxxxx>
> Cc: Matthias Brugger <matthias.bgg@xxxxxxxxx>
> Cc: AngeloGioacchino Del Regno <
> angelogioacchino.delregno@xxxxxxxxxxxxx>
>
> ---
>
> 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,