Re: [PATCH 11/14] drm/i915/dp: Program AS SDP DB[1:0] for PR with Link off

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

On Mon, Feb 23, 2026 at 07:14:28PM +0530, Ankit Nautiyal wrote:
> For Panel Replay with AUX-less ALPM (link-off PR), the source must send
> Adaptive-Sync SDP v2. Program DB[1:0] per DP spec v2.1:
> - VRR AVT: 00b (variable VTotal)
> - VRR FAVT: 10b/11b (TRR not reached/reached)
> - Fixed timing with PR link-off (VRR off): 01b (AS disabled; VTotal fixed)
> 
> Select SDP version v2 whenever PR link-off or VRR is active, otherwise v1,
> and program the AS SDP DB[1:0] bits.
> 
> Also, drop the redundant target_rr assignment.
> 
> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_dp.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 5952db6197cf..ad2aceb526ff 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -3139,7 +3139,7 @@ static void intel_dp_compute_as_sdp(struct intel_dp *intel_dp,
>  	as_sdp->duration_incr_ms = 0;
>  	as_sdp->version = 0x2;
>  
> -	if (crtc_state->vrr.enable)
> +	if (crtc_state->vrr.enable || intel_psr_is_pr_with_link_off(crtc_state))
>  		as_sdp->version = 0x2;
>  	else
>  		as_sdp->version = 0x1;
> @@ -3154,9 +3154,10 @@ static void intel_dp_compute_as_sdp(struct intel_dp *intel_dp,
>  		as_sdp->mode = DP_AS_SDP_FAVT_TRR_REACHED;
>  		as_sdp->target_rr = drm_mode_vrefresh(adjusted_mode);
>  		as_sdp->target_rr_divider = true;
> -	} else {
> +	} else if (crtc_state->vrr.enable) {
>  		as_sdp->mode = DP_AS_SDP_AVT_DYNAMIC_VTOTAL;
> -		as_sdp->target_rr = 0;
> +	} else if (intel_psr_is_pr_with_link_off(crtc_state)) {
> +		as_sdp->mode = DP_AS_SDP_AVT_FIXED_VTOTAL;
>  	}
 else {
  what now?
 }
>  }
>  
> -- 
> 2.45.2

-- 
Ville Syrjälä
Intel