[PATCH v2 03/12] drm/i915/psr: Read all Panel Replay capability registers from DPCD

[Nautiyal, Ankit K]

On 5/20/2025 10:23 PM, Jouni Högander wrote:
> There are several Panel Replay capability register in DPCD. Read them
> all for later use.
>
> v2:
>    - avoid using hardcoded indices
>    - read all Panel Replay capability registers
>
> Signed-off-by: Jouni Högander <jouni.hogander at intel.com>

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


> ---
>   .../drm/i915/display/intel_display_types.h    |  4 +++-
>   drivers/gpu/drm/i915/display/intel_psr.c      | 20 ++++++++++++-------
>   2 files changed, 16 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> index b8836d29a721..9334fcd77072 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -1669,7 +1669,9 @@ struct intel_dp {
>   	bool use_max_params;
>   	u8 dpcd[DP_RECEIVER_CAP_SIZE];
>   	u8 psr_dpcd[EDP_PSR_RECEIVER_CAP_SIZE];
> -	u8 pr_dpcd;
> +	u8 pr_dpcd[DP_PANEL_REPLAY_CAP_SIZE];
> +#define INTEL_PR_DPCD_INDEX(pr_dpcd_register)	((pr_dpcd_register) - DP_PANEL_REPLAY_CAP_SUPPORT)
> +
>   	u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS];
>   	u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE];
>   	u8 lttpr_common_caps[DP_LTTPR_COMMON_CAP_SIZE];
> diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
> index 0cfdeff268f9..1072549649cd 100644
> --- a/drivers/gpu/drm/i915/display/intel_psr.c
> +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> @@ -608,7 +608,8 @@ static void _panel_replay_init_dpcd(struct intel_dp *intel_dp)
>   			return;
>   		}
>   
> -		if (!(intel_dp->pr_dpcd & DP_PANEL_REPLAY_EARLY_TRANSPORT_SUPPORT)) {
> +		if (!(intel_dp->pr_dpcd[INTEL_PR_DPCD_INDEX(DP_PANEL_REPLAY_CAP_SUPPORT)] &
> +		      DP_PANEL_REPLAY_EARLY_TRANSPORT_SUPPORT)) {
>   			drm_dbg_kms(display->drm,
>   				    "Panel doesn't support early transport, eDP Panel Replay not possible\n");
>   			return;
> @@ -617,7 +618,8 @@ static void _panel_replay_init_dpcd(struct intel_dp *intel_dp)
>   
>   	intel_dp->psr.sink_panel_replay_support = true;
>   
> -	if (intel_dp->pr_dpcd & DP_PANEL_REPLAY_SU_SUPPORT)
> +	if (intel_dp->pr_dpcd[INTEL_PR_DPCD_INDEX(DP_PANEL_REPLAY_CAP_SUPPORT)] &
> +	    DP_PANEL_REPLAY_SU_SUPPORT)
>   		intel_dp->psr.sink_panel_replay_su_support = true;
>   
>   	drm_dbg_kms(display->drm,
> @@ -676,10 +678,12 @@ void intel_psr_init_dpcd(struct intel_dp *intel_dp)
>   {
>   	drm_dp_dpcd_read(&intel_dp->aux, DP_PSR_SUPPORT, intel_dp->psr_dpcd,
>   			 sizeof(intel_dp->psr_dpcd));
> -	drm_dp_dpcd_readb(&intel_dp->aux, DP_PANEL_REPLAY_CAP_SUPPORT,
> -			  &intel_dp->pr_dpcd);
>   
> -	if (intel_dp->pr_dpcd & DP_PANEL_REPLAY_SUPPORT)
> +	drm_dp_dpcd_read(&intel_dp->aux, DP_PANEL_REPLAY_CAP_SUPPORT,
> +			 &intel_dp->pr_dpcd, sizeof(intel_dp->pr_dpcd));
> +
> +	if (intel_dp->pr_dpcd[INTEL_PR_DPCD_INDEX(DP_PANEL_REPLAY_CAP_SUPPORT)] &
> +	    DP_PANEL_REPLAY_SUPPORT)
>   		_panel_replay_init_dpcd(intel_dp);
>   
>   	if (intel_dp->psr_dpcd[0])
> @@ -736,7 +740,8 @@ static bool psr2_su_region_et_valid(struct intel_dp *intel_dp, bool panel_replay
>   		return false;
>   
>   	return panel_replay ?
> -		intel_dp->pr_dpcd & DP_PANEL_REPLAY_EARLY_TRANSPORT_SUPPORT :
> +		intel_dp->pr_dpcd[INTEL_PR_DPCD_INDEX(DP_PANEL_REPLAY_CAP_SUPPORT)] &
> +		DP_PANEL_REPLAY_EARLY_TRANSPORT_SUPPORT :
>   		intel_dp->psr_dpcd[0] == DP_PSR2_WITH_Y_COORD_ET_SUPPORTED &&
>   		psr2_su_region_et_global_enabled(intel_dp);
>   }
> @@ -3916,7 +3921,8 @@ static void intel_psr_sink_capability(struct intel_dp *intel_dp,
>   	seq_printf(m, ", Panel Replay = %s", str_yes_no(psr->sink_panel_replay_support));
>   	seq_printf(m, ", Panel Replay Selective Update = %s",
>   		   str_yes_no(psr->sink_panel_replay_su_support));
> -	if (intel_dp->pr_dpcd & DP_PANEL_REPLAY_EARLY_TRANSPORT_SUPPORT)
> +	if (intel_dp->pr_dpcd[INTEL_PR_DPCD_INDEX(DP_PANEL_REPLAY_CAP_SUPPORT)] &
> +	    DP_PANEL_REPLAY_EARLY_TRANSPORT_SUPPORT)
>   		seq_printf(m, " (Early Transport)");
>   	seq_printf(m, "\n");
>   }