Re: [PATCH v11 05/10] drm/mediatek: Add MT8195 Embedded DisplayPort driver

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

On Mon, 2022-06-20 at 11:19 +0800, CK Hu wrote:
> On Mon, 2022-06-20 at 11:12 +0800, CK Hu wrote:
> > On Fri, 2022-06-10 at 18:55 +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>
> > > [Bo-Chen: Cleanup the drivers and modify comments from reviewers]
> > > Signed-off-by: Bo-Chen Chen <rex-bc.chen@mediatek.com>
> > > ---
> > 
> > [snip]
> > 
> > > +
> > > +static void mtk_dp_calculate_pixrate(struct mtk_dp *mtk_dp)
> > > +{
> > > +	u8 target_frame_rate = 60;
> > > +	u32 target_pixel_clk;
> > > +	struct drm_display_mode mode;
> > > +	struct mtk_dp_timings *timings = &mtk_dp->info.timings;
> > > +
> > > +	drm_display_mode_from_videomode(&timings->vm, &mode);
> > > +
> > > +	if (mtk_dp->info.timings.frame_rate > 0) {
> > > +		target_frame_rate = mtk_dp->info.timings.frame_rate;
> > > +		target_pixel_clk = mode.htotal * mode.vtotal *
> > > +				   target_frame_rate;
> > > +	} else if (mtk_dp->info.timings.pix_rate_khz > 0) {
> > > +		target_pixel_clk = mtk_dp->info.timings.pix_rate_khz *
> > > 1000;
> > > +	} else {
> > > +		target_pixel_clk = mode.htotal * mode.vtotal *
> > > +				   target_frame_rate;
> > > +	}
> > > +
> > > +	mtk_dp->info.timings.pix_rate_khz = target_pixel_clk / 1000;
> > 
> > It seems that pix_rate_khz is used only here and does not used in
> > another place, so pix_rate_khz is useless, remove it.
> 
> It seems that frame_rate is also redundant, so remove it.
> 
> Regards,
> CK
> 

I think we do use this variable in mtk_dp_parse_drm_mode_timings()
We use this variable to get target framerate.

BRs,
Bo-Chen

> > 
> > Regards,
> > CK
> > 
> > > +}
> > > +
> 
>