Re: [PATCH] drm/i915/cx0: Use the consolidated HDMI tables

["Nautiyal, Ankit K" <ankit.k.nautiyal@intel.com>]

On 12/16/2025 1:57 PM, Suraj Kandpal wrote:
> Use the consolidated HDMI tables before we try to compute them via
> algorithm. The reason is that these are the ideal values and even
> though the values calculated via the HDMI algorithm are correct but
> not always ideal.


Will be good to mention that this change is for C20 PHY. For others we 
are already following the same policy.


>
> Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
> ---
>   drivers/gpu/drm/i915/display/intel_cx0_phy.c | 13 ++++++++-----
>   1 file changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_cx0_phy.c b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
> index f6d69627154e..d0f764189567 100644
> --- a/drivers/gpu/drm/i915/display/intel_cx0_phy.c
> +++ b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
> @@ -2671,15 +2671,18 @@ static int intel_c20pll_calc_state(const struct intel_crtc_state *crtc_state,
>   	hw_state->cx0pll.use_c10 = false;
>   	hw_state->cx0pll.lane_count = crtc_state->lane_count;
>   
> -	/* try computed C20 HDMI tables before using consolidated tables */
> -	if (!is_dp)
> -		/* TODO: Update SSC state for HDMI as well */
> -		err = intel_c20_compute_hdmi_tmds_pll(crtc_state, &hw_state->cx0pll.c20);
> -
> +	/*
> +	 * Try the ideal C20 HDMI tables before trying to compute them since the values
> +	 * calculated even though would be correct but not ideal
> +	 */
>   	if (err)
>   		err = intel_c20pll_calc_state_from_table(crtc_state, encoder,
>   							 &hw_state->cx0pll);
>   
> +	if (!is_dp && err)
> +		err = intel_c20_compute_hdmi_tmds_pll(crtc_state, &hw_state->cx0pll.c20);
> +		/* TODO: Update SSC state for HDMI as well */

Nitpick: Let this comment be before the intel_c20_compute_hdmi_tmds_pl() 
call to match existing code.

In any case the change looks good to me.

Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>


Regards,

Ankit

> +
>   	if (err)
>   		return err;
>