Re: [PATCH v10 02/16] drm/mediatek: gamma: Reduce indentation in mtk_gamma_set_common()

[CK Hu (胡俊光)]

Hi, Angelo:

On Fri, 2023-08-04 at 09:28 +0200, AngeloGioacchino Del Regno wrote:
> Invert the check for state->gamma_lut and move it at the beginning
> of the function to reduce indentation: this prepares the code for
> keeping readability on later additions.
> 
> This commit brings no functional changes.

Reviewed-by: CK Hu <ck.hu@xxxxxxxxxxxx>

> 
> Signed-off-by: AngeloGioacchino Del Regno <
> angelogioacchino.delregno@xxxxxxxxxxxxx>
> Reviewed-by: Jason-JH.Lin <jason-jh.lin@xxxxxxxxxxxx>
> Reviewed-by: Alexandre Mergnat <amergnat@xxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 45 ++++++++++++---------
> --
>  1 file changed, 23 insertions(+), 22 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> index d42cc0698d83..47751864bd5c 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
> @@ -64,6 +64,10 @@ void mtk_gamma_set_common(struct device *dev, void
> __iomem *regs, struct drm_crt
>  	u32 word;
>  	u32 diff[3] = {0};
>  
> +	/* If there's no gamma lut there's nothing to do here. */
> +	if (!state->gamma_lut)
> +		return;
> +
>  	/* If we're called from AAL, dev is NULL */
>  	gamma = dev ? dev_get_drvdata(dev) : NULL;
>  
> @@ -72,29 +76,26 @@ void mtk_gamma_set_common(struct device *dev,
> void __iomem *regs, struct drm_crt
>  	else
>  		lut_diff = false;
>  
> -	if (state->gamma_lut) {
> -		reg = readl(regs + DISP_GAMMA_CFG);
> -		reg = reg | GAMMA_LUT_EN;
> -		writel(reg, regs + DISP_GAMMA_CFG);
> -		lut_base = regs + DISP_GAMMA_LUT;
> -		lut = (struct drm_color_lut *)state->gamma_lut->data;
> -		for (i = 0; i < MTK_LUT_SIZE; i++) {
> -
> -			if (!lut_diff || (i % 2 == 0)) {
> -				word = (((lut[i].red >> 6) &
> LUT_10BIT_MASK) << 20) +
> -					(((lut[i].green >> 6) &
> LUT_10BIT_MASK) << 10) +
> -					((lut[i].blue >> 6) &
> LUT_10BIT_MASK);
> -			} else {
> -				diff[0] = (lut[i].red >> 6) - (lut[i -
> 1].red >> 6);
> -				diff[1] = (lut[i].green >> 6) - (lut[i
> - 1].green >> 6);
> -				diff[2] = (lut[i].blue >> 6) - (lut[i -
> 1].blue >> 6);
> -
> -				word = ((diff[0] & LUT_10BIT_MASK) <<
> 20) +
> -					((diff[1] & LUT_10BIT_MASK) <<
> 10) +
> -					(diff[2] & LUT_10BIT_MASK);
> -			}
> -			writel(word, (lut_base + i * 4));
> +	reg = readl(regs + DISP_GAMMA_CFG);
> +	reg = reg | GAMMA_LUT_EN;
> +	writel(reg, regs + DISP_GAMMA_CFG);
> +	lut_base = regs + DISP_GAMMA_LUT;
> +	lut = (struct drm_color_lut *)state->gamma_lut->data;
> +	for (i = 0; i < MTK_LUT_SIZE; i++) {
> +		if (!lut_diff || (i % 2 == 0)) {
> +			word = (((lut[i].red >> 6) & LUT_10BIT_MASK) <<
> 20) +
> +				(((lut[i].green >> 6) & LUT_10BIT_MASK)
> << 10) +
> +				((lut[i].blue >> 6) & LUT_10BIT_MASK);
> +		} else {
> +			diff[0] = (lut[i].red >> 6) - (lut[i - 1].red
> >> 6);
> +			diff[1] = (lut[i].green >> 6) - (lut[i -
> 1].green >> 6);
> +			diff[2] = (lut[i].blue >> 6) - (lut[i - 1].blue
> >> 6);
> +
> +			word = ((diff[0] & LUT_10BIT_MASK) << 20) +
> +				((diff[1] & LUT_10BIT_MASK) << 10) +
> +				(diff[2] & LUT_10BIT_MASK);
>  		}
> +		writel(word, (lut_base + i * 4));
>  	}
>  }
>