Re: [PATCH 21/35] drm/i915/display: Enable MSA Ignore Timing PAR only when in not fixed_rr mode

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Fri, Jan 24, 2025 at 08:30:06PM +0530, Ankit Nautiyal wrote:
> MSA Ignore Timing PAR enable is set in the DP sink when we enable variable
> refresh rate. When using VRR timing generator for fixed refresh rate
> we do not want to ignore the mode timings, as the refresh rate is still
> fixed. Modify the checks to enable MSA Ignore Timing PAR only when not
> in fixed_rr mode.
> 
> v2: Initialize enable_msa_timing_par_ignore to false.
> 
> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_ddi.c              | 2 +-
>  drivers/gpu/drm/i915/display/intel_dp_link_training.c | 8 +++++++-
>  2 files changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index d48a3108f363..dac953b2af31 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -2281,7 +2281,7 @@ static void intel_dp_sink_set_msa_timing_par_ignore_state(struct intel_dp *intel
>  {
>  	struct intel_display *display = to_intel_display(intel_dp);
>  
> -	if (!intel_vrrtg_is_enabled(crtc_state))
> +	if (!intel_vrrtg_is_enabled(crtc_state) || crtc_state->vrr.flipline == crtc_state->vrr.vmax)
>  		return;
>  
>  	if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_DOWNSPREAD_CTRL,
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.c b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
> index 9cb22baafeeb..b8063807fd34 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
> @@ -724,8 +724,14 @@ void intel_dp_link_training_set_mode(struct intel_dp *intel_dp, int link_rate, b
>  static void intel_dp_update_downspread_ctrl(struct intel_dp *intel_dp,
>  					    const struct intel_crtc_state *crtc_state)
>  {
> +	bool enable_msa_timing_par_ignore = false;
> +
> +	/* Enable MSA TIMING PAR IGNORE only in non fixed_rr mode */
> +	if (crtc_state->vrr.flipline && crtc_state->vrr.flipline != crtc_state->vrr.vmax)
> +		enable_msa_timing_par_ignore = true;
> +
>  	intel_dp_link_training_set_mode(intel_dp,
> -					crtc_state->port_clock, crtc_state->vrr.flipline);
> +					crtc_state->port_clock, enable_msa_timing_par_ignore);

We only set this during link training, so this won't work for fastsets.
I think what we want is to just always set this when the timings are in
the VRR range.

>  }
>  
>  void intel_dp_link_training_set_bw(struct intel_dp *intel_dp,
> -- 
> 2.45.2

-- 
Ville Syrjälä
Intel