Re: [PATCH v13 05/10] drm/mediatek: Add MT8195 Embedded DisplayPort driver

[Rex-BC Chen <rex-bc.chen@mediatek.com>]

On Thu, 2022-07-07 at 16:00 +0800, CK Hu wrote:
> Hi, Bo-Chen:
> 
> On Fri, 2022-07-01 at 14:28 +0800, Bo-Chen Chen wrote:
> > From: Markus Schneider-Pargmann <msp@baylibre.com>
> > 
> > This patch adds a embedded displayport driver for the MediaTek
> > mt8195
> > SoC.
> > 
> > It supports the MT8195, the embedded DisplayPort units. It offers
> > DisplayPort 1.4 with up to 4 lanes.
> > 
> > The driver creates a child device for the phy. The child device
> > will
> > never exist without the parent being active. As they are sharing a
> > register range, the parent passes a regmap pointer to the child so
> > that
> > both can work with the same register range. The phy driver sets
> > device
> > data that is read by the parent to get the phy device that can be
> > used
> > to control the phy properties.
> > 
> > This driver is based on an initial version by
> > Jitao shi <jitao.shi@mediatek.com>
> > 
> > Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
> > Signed-off-by: Guillaume Ranquet <granquet@baylibre.com>
> > Signed-off-by: Bo-Chen Chen <rex-bc.chen@mediatek.com>
> > ---
> 
> [snip]
> 
> > +
> > +static int mtk_dp_set_color_format(struct mtk_dp *mtk_dp,
> > +				   enum dp_pixelformat color_format)
> > +{
> > +	u32 val;
> > +
> > +	/* update MISC0 */
> > +	mtk_dp_update_bits(mtk_dp, MTK_DP_ENC0_P0_3034,
> > +			   color_format << DP_TEST_COLOR_FORMAT_SHIFT,
> > +			   DP_TEST_COLOR_FORMAT_MASK);
> > +
> > +	switch (color_format) {
> > +	case DP_PIXELFORMAT_YUV422:
> > +		val = PIXEL_ENCODE_FORMAT_DP_ENC0_P0_YCBCR422;
> > +		break;
> > +	case DP_PIXELFORMAT_RGB:
> > +		val = PIXEL_ENCODE_FORMAT_DP_ENC0_P0_RGB;
> > +		break;
> > +	default:
> 
> The default case would never happen, remove it.
> 
> Regards,
> CK
> 

Hello CK,

after removing default, it will build error because we do not handle
other 5 enum in enum dp_pixelformat.

"error: 5 enumeration values not handled in switch"

Therefore, I will keep this.

BRs,
Bo-Chen

> > +		drm_warn(mtk_dp->drm_dev, "Unsupported color format:
> > %d\n",
> > +			 color_format);
> > +		return -EINVAL;
> > +	}
> > +
> > +	mtk_dp_update_bits(mtk_dp, MTK_DP_ENC0_P0_303C,
> > +			   val, PIXEL_ENCODE_FORMAT_DP_ENC0_P0_MASK);
> > +	return 0;
> > +}
> > +
> 
>