Re: [PATCH v5 08/15] drm/rockchip: vop2: Avoid DCLK source switch for 10-bit YUV422 output

[Daniel Stone]

Hi,

On Tue, 13 Oct 2026 at 23:51, Cristian Ciocaltea
<cristian.ciocaltea@xxxxxxxxxxxxx> wrote:
>         if (vop2->pll_hdmiphy0 || vop2->pll_hdmiphy1) {
> -               unsigned int bpc = vcstate->output_bpc ?: 8;
> +               /*
> +                * YUV422 always transmits two 12-bit components per clock
> +                * cycle, regardless of the color depth, which from a rate
> +                * perspective is equivalent to three 8-bit RGB components.
> +                * Force 8 bpc here so the bandwidth check reflects the actual
> +                * TMDS rate and avoids an unnecessary DCLK source switch.
> +                */
> +               unsigned int bpc = vcstate->output_mode == ROCKCHIP_OUT_MODE_YUV422 ?
> +                                       8 : (vcstate->output_bpc ?: 8);

The nested ternary is pretty violent; please write it out explicitly.
Either way, the equivalent clock adjustment for YUV420 is handled in
the setup_intf_mux() handler, so would it be better for YUV422 to also
live there, rather than mashed in with bpc here?

Cheers,
Daniel