Re: [PATCH 2/2] drm/i915/psr: Do not disable Panel Replay if PSR2 is disabled

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Mon, Jul 07, 2025 at 01:47:33PM +0300, Jouni Högander wrote:
> Currently disabling PSR2 via enable_psr module parameter causes Panel
> Replay being disabled as well. This patch changes this by still allowing
> Panel Replay even if PSR2 is disabled.
> 
> After this patch enable_psr module parameter values are:
> 
> -1 = PSR1 : yes, PSR2 = yes, Panel Replay : yes
>  0 = PSR1 : no,  PSR2 = no,  Panel Replay : no
>  1 = PSR1 : yes, PSR2 = no,  Panel Replay : yes
>  2 = PSR1 : yes, PSR2 = yes, Panel Replay : no
> 
> Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
> ---
>  .../drm/i915/display/intel_display_params.c   |  3 +--
>  drivers/gpu/drm/i915/display/intel_psr.c      | 20 +++++++++++++------
>  2 files changed, 15 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_params.c b/drivers/gpu/drm/i915/display/intel_display_params.c
> index 75316247ee8a..1ba17ea40bba 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_params.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_params.c
> @@ -116,8 +116,7 @@ intel_display_param_named_unsafe(enable_fbc, int, 0400,
>  	"(default: -1 (use per-chip default))");
>  
>  intel_display_param_named_unsafe(enable_psr, int, 0400,
> -	"Enable PSR "
> -	"(0=disabled, 1=enable up to PSR1, 2=enable up to PSR2) "
> +	"Enable PSR (0=disabled, 1=disable PSR2, 2=disable Panel Replay)"

What about a bit mask?

PSR1 = BIT0
PSR2 = BIT1 (PSR2 infers PSR1 enabled)
PANEL_REPLAY = BIT2 (also infers PSR1(and 2?) enabled)

(Peraps even bit3 for early transport?)

This is backwards compatible because

0 = disabled,
1 = up to psr1,
2 = up to psr2, (no panel replay)
3 = up to psr2, (same as 2)
4 = panel replay on
5 = same as 5

>  	"Default: -1 (use per-chip default)");
>  
>  intel_display_param_named(psr_safest_params, bool, 0400,
> diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
> index a2b5688f0c82..3215a11baa66 100644
> --- a/drivers/gpu/drm/i915/display/intel_psr.c
> +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> @@ -254,13 +254,15 @@ static bool psr2_global_enabled(struct intel_dp *intel_dp)
>  {
>  	struct intel_display *display = to_intel_display(intel_dp);
>  
> +	return display->params.enable_psr != 1;
> +}
> +
> +static bool sel_update_global_enabled(struct intel_dp *intel_dp)
> +{
>  	switch (intel_dp->psr.debug & I915_PSR_DEBUG_MODE_MASK) {
> -	case I915_PSR_DEBUG_DISABLE:
>  	case I915_PSR_DEBUG_FORCE_PSR1:
>  		return false;
>  	default:
> -		if (display->params.enable_psr == 1)
> -			return false;
>  		return true;
>  	}
>  }
> @@ -269,7 +271,7 @@ static bool panel_replay_global_enabled(struct intel_dp *intel_dp)
>  {
>  	struct intel_display *display = to_intel_display(intel_dp);
>  
> -	if ((display->params.enable_psr != -1) ||
> +	if (display->params.enable_psr == 2 ||
>  	    (intel_dp->psr.debug & I915_PSR_DEBUG_PANEL_REPLAY_DISABLE))
>  		return false;
>  	return true;
> @@ -1415,6 +1417,12 @@ static bool intel_psr2_config_valid(struct intel_dp *intel_dp,
>  	if (!intel_dp->psr.sink_psr2_support)
>  		return false;
>  
> +	if (!psr2_global_enabled(intel_dp)) {
> +		drm_dbg_kms(display->drm,
> +			    "PSR2 disabled by flag\n");
> +		return false;
> +	}
> +
>  	/* JSL and EHL only supports eDP 1.3 */
>  	if (display->platform.jasperlake || display->platform.elkhartlake) {
>  		drm_dbg_kms(display->drm, "PSR2 not supported by phy\n");
> @@ -1517,7 +1525,7 @@ static bool intel_sel_update_config_valid(struct intel_dp *intel_dp,
>  		goto unsupported;
>  	}
>  
> -	if (!psr2_global_enabled(intel_dp)) {
> +	if (!sel_update_global_enabled(intel_dp)) {
>  		drm_dbg_kms(display->drm,
>  			    "Selective update disabled by flag\n");
>  		goto unsupported;
> @@ -1664,7 +1672,7 @@ void intel_psr_compute_config(struct intel_dp *intel_dp,
>  	u8 active_pipes = 0;
>  
>  	if (!psr_global_enabled(intel_dp)) {
> -		drm_dbg_kms(display->drm, "PSR disabled by flag\n");
> +		drm_dbg_kms(display->drm, "PSR/Panel Replay disabled by flag\n");
>  		return;
>  	}
>  
> -- 
> 2.43.0
>