diff mbox series

[RFC,2/3] drm/i915/alpm: Add compute config for lobf

Message ID 20240304074303.202882-3-animesh.manna@intel.com (mailing list archive)
State New, archived
Headers show
Series Link off between frames for edp | expand

Commit Message

Animesh Manna March 4, 2024, 7:43 a.m. UTC
Link Off Between Active Frames, is a new feature for eDP
that allows the panel to go to lower power state after
transmission of data. This is a feature on top of ALPM, AS SDP.
Add compute config during atomic-check phase.

Signed-off-by: Animesh Manna <animesh.manna@intel.com>
---
 .../drm/i915/display/intel_display_types.h    |  3 ++
 drivers/gpu/drm/i915/display/intel_dp.c       |  1 +
 drivers/gpu/drm/i915/display/intel_psr.c      | 45 +++++++++++++++++++
 drivers/gpu/drm/i915/display/intel_psr.h      |  3 ++
 4 files changed, 52 insertions(+)

Comments

Jani Nikula March 4, 2024, 5:33 p.m. UTC | #1
On Mon, 04 Mar 2024, Animesh Manna <animesh.manna@intel.com> wrote:
> Link Off Between Active Frames, is a new feature for eDP
> that allows the panel to go to lower power state after
> transmission of data. This is a feature on top of ALPM, AS SDP.
> Add compute config during atomic-check phase.
>
> Signed-off-by: Animesh Manna <animesh.manna@intel.com>
> ---
>  .../drm/i915/display/intel_display_types.h    |  3 ++
>  drivers/gpu/drm/i915/display/intel_dp.c       |  1 +
>  drivers/gpu/drm/i915/display/intel_psr.c      | 45 +++++++++++++++++++
>  drivers/gpu/drm/i915/display/intel_psr.h      |  3 ++
>  4 files changed, 52 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> index d473d8dca90a..4d2161eeb686 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -1851,6 +1851,9 @@ struct intel_dp {
>  		u8 silence_period_sym_clocks;
>  		u8 lfps_half_cycle_num_of_syms;
>  	} alpm_parameters;
> +
> +	/* LOBF flags*/
> +	bool lobf_supported;
>  };
>  
>  enum lspcon_vendor {
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 8304ef912767..e34b70d88b9a 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -2979,6 +2979,7 @@ intel_dp_compute_config(struct intel_encoder *encoder,
>  	intel_vrr_compute_config(pipe_config, conn_state);
>  	intel_dp_compute_as_sdp(intel_dp, pipe_config, conn_state);
>  	intel_psr_compute_config(intel_dp, pipe_config, conn_state);
> +	intel_psr_lobf_compute_config(intel_dp, pipe_config, conn_state);
>  	intel_dp_drrs_compute_config(connector, pipe_config, link_bpp_x16);
>  	intel_dp_compute_vsc_sdp(intel_dp, pipe_config, conn_state);
>  	intel_dp_compute_hdr_metadata_infoframe_sdp(intel_dp, pipe_config, conn_state);
> diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
> index 4adcddba69c1..c08bffc2921a 100644
> --- a/drivers/gpu/drm/i915/display/intel_psr.c
> +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> @@ -436,6 +436,16 @@ static bool intel_dp_get_alpm_status(struct intel_dp *intel_dp)
>  	return alpm_caps & DP_ALPM_CAP;
>  }
>  
> +static bool intel_dp_get_aux_less_alpm_status(struct intel_dp *intel_dp)
> +{
> +	u8 alpm_caps = 0;
> +
> +	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_RECEIVER_ALPM_CAP,
> +			      &alpm_caps) != 1)

The compute config path must not access the hardware.

BR,
Jani.

> +		return false;
> +	return alpm_caps & DP_ALPM_AUX_LESS_CAP;
> +}
> +
>  static u8 intel_dp_get_sink_sync_latency(struct intel_dp *intel_dp)
>  {
>  	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
> @@ -1569,6 +1579,41 @@ void intel_psr_compute_config(struct intel_dp *intel_dp,
>  	crtc_state->has_psr2 = intel_psr2_config_valid(intel_dp, crtc_state);
>  }
>  
> +void intel_psr_lobf_compute_config(struct intel_dp *intel_dp,
> +			       struct intel_crtc_state *crtc_state,
> +			       struct drm_connector_state *conn_state)
> +{
> +	struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
> +	int waketime_in_lines, first_sdp_position;
> +	int context_latency, guardband;
> +	bool auxless_alpm;
> +
> +	intel_dp->lobf_supported = false;
> +
> +	if (!intel_dp_is_edp(intel_dp))
> +		return;
> +
> +	if (!intel_dp_as_sdp_supported(intel_dp))
> +		return;
> +
> +	if (CAN_PSR(intel_dp) || CAN_PANEL_REPLAY(intel_dp))
> +		return;
> +
> +	if (_compute_alpm_params(intel_dp, crtc_state)) {
> +		context_latency = adjusted_mode->crtc_vblank_start - adjusted_mode->crtc_vdisplay;
> +		guardband = adjusted_mode->crtc_vtotal - adjusted_mode->crtc_vdisplay - context_latency;
> +		first_sdp_position = adjusted_mode->crtc_vtotal - adjusted_mode->crtc_vsync_start;
> +		auxless_alpm = intel_dp_get_aux_less_alpm_status(intel_dp);
> +		if (auxless_alpm)
> +			waketime_in_lines = intel_dp->alpm_parameters.io_wake_lines;
> +		else
> +			waketime_in_lines = intel_dp->alpm_parameters.aux_less_wake_lines;
> +
> +		if ((context_latency + guardband) > (first_sdp_position + waketime_in_lines))
> +			intel_dp->lobf_supported = true;
> +	}
> +}
> +
>  void intel_psr_get_config(struct intel_encoder *encoder,
>  			  struct intel_crtc_state *pipe_config)
>  {
> diff --git a/drivers/gpu/drm/i915/display/intel_psr.h b/drivers/gpu/drm/i915/display/intel_psr.h
> index cde781df84d5..4bb77295288f 100644
> --- a/drivers/gpu/drm/i915/display/intel_psr.h
> +++ b/drivers/gpu/drm/i915/display/intel_psr.h
> @@ -40,6 +40,9 @@ void intel_psr_init(struct intel_dp *intel_dp);
>  void intel_psr_compute_config(struct intel_dp *intel_dp,
>  			      struct intel_crtc_state *crtc_state,
>  			      struct drm_connector_state *conn_state);
> +void intel_psr_lobf_compute_config(struct intel_dp *intel_dp,
> +				   struct intel_crtc_state *crtc_state,
> +				   struct drm_connector_state *conn_state);
>  void intel_psr_get_config(struct intel_encoder *encoder,
>  			  struct intel_crtc_state *pipe_config);
>  void intel_psr_irq_handler(struct intel_dp *intel_dp, u32 psr_iir);
Animesh Manna March 5, 2024, 7:31 a.m. UTC | #2
> -----Original Message-----
> From: Jani Nikula <jani.nikula@linux.intel.com>
> Sent: Monday, March 4, 2024 11:03 PM
> To: Manna, Animesh <animesh.manna@intel.com>; intel-
> gfx@lists.freedesktop.org
> Cc: Hogander, Jouni <jouni.hogander@intel.com>; Murthy, Arun R
> <arun.r.murthy@intel.com>; Manna, Animesh <animesh.manna@intel.com>
> Subject: Re: [RFC 2/3] drm/i915/alpm: Add compute config for lobf
> 
> On Mon, 04 Mar 2024, Animesh Manna <animesh.manna@intel.com>
> wrote:
> > Link Off Between Active Frames, is a new feature for eDP that allows
> > the panel to go to lower power state after transmission of data. This
> > is a feature on top of ALPM, AS SDP.
> > Add compute config during atomic-check phase.
> >
> > Signed-off-by: Animesh Manna <animesh.manna@intel.com>
> > ---
> >  .../drm/i915/display/intel_display_types.h    |  3 ++
> >  drivers/gpu/drm/i915/display/intel_dp.c       |  1 +
> >  drivers/gpu/drm/i915/display/intel_psr.c      | 45 +++++++++++++++++++
> >  drivers/gpu/drm/i915/display/intel_psr.h      |  3 ++
> >  4 files changed, 52 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> > b/drivers/gpu/drm/i915/display/intel_display_types.h
> > index d473d8dca90a..4d2161eeb686 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > @@ -1851,6 +1851,9 @@ struct intel_dp {
> >  		u8 silence_period_sym_clocks;
> >  		u8 lfps_half_cycle_num_of_syms;
> >  	} alpm_parameters;
> > +
> > +	/* LOBF flags*/
> > +	bool lobf_supported;
> >  };
> >
> >  enum lspcon_vendor {
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> > b/drivers/gpu/drm/i915/display/intel_dp.c
> > index 8304ef912767..e34b70d88b9a 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > @@ -2979,6 +2979,7 @@ intel_dp_compute_config(struct intel_encoder
> *encoder,
> >  	intel_vrr_compute_config(pipe_config, conn_state);
> >  	intel_dp_compute_as_sdp(intel_dp, pipe_config, conn_state);
> >  	intel_psr_compute_config(intel_dp, pipe_config, conn_state);
> > +	intel_psr_lobf_compute_config(intel_dp, pipe_config, conn_state);
> >  	intel_dp_drrs_compute_config(connector, pipe_config,
> link_bpp_x16);
> >  	intel_dp_compute_vsc_sdp(intel_dp, pipe_config, conn_state);
> >  	intel_dp_compute_hdr_metadata_infoframe_sdp(intel_dp,
> pipe_config,
> > conn_state); diff --git a/drivers/gpu/drm/i915/display/intel_psr.c
> > b/drivers/gpu/drm/i915/display/intel_psr.c
> > index 4adcddba69c1..c08bffc2921a 100644
> > --- a/drivers/gpu/drm/i915/display/intel_psr.c
> > +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> > @@ -436,6 +436,16 @@ static bool intel_dp_get_alpm_status(struct
> intel_dp *intel_dp)
> >  	return alpm_caps & DP_ALPM_CAP;
> >  }
> >
> > +static bool intel_dp_get_aux_less_alpm_status(struct intel_dp
> > +*intel_dp) {
> > +	u8 alpm_caps = 0;
> > +
> > +	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_RECEIVER_ALPM_CAP,
> > +			      &alpm_caps) != 1)
> 
> The compute config path must not access the hardware.

Sure, will put in init_connector() and store in a variable.

Regards,
Animesh

> 
> BR,
> Jani.
> 
> > +		return false;
> > +	return alpm_caps & DP_ALPM_AUX_LESS_CAP; }
> > +
> >  static u8 intel_dp_get_sink_sync_latency(struct intel_dp *intel_dp)
> > {
> >  	struct drm_i915_private *i915 = dp_to_i915(intel_dp); @@ -1569,6
> > +1579,41 @@ void intel_psr_compute_config(struct intel_dp *intel_dp,
> >  	crtc_state->has_psr2 = intel_psr2_config_valid(intel_dp,
> > crtc_state);  }
> >
> > +void intel_psr_lobf_compute_config(struct intel_dp *intel_dp,
> > +			       struct intel_crtc_state *crtc_state,
> > +			       struct drm_connector_state *conn_state) {
> > +	struct drm_display_mode *adjusted_mode = &crtc_state-
> >hw.adjusted_mode;
> > +	int waketime_in_lines, first_sdp_position;
> > +	int context_latency, guardband;
> > +	bool auxless_alpm;
> > +
> > +	intel_dp->lobf_supported = false;
> > +
> > +	if (!intel_dp_is_edp(intel_dp))
> > +		return;
> > +
> > +	if (!intel_dp_as_sdp_supported(intel_dp))
> > +		return;
> > +
> > +	if (CAN_PSR(intel_dp) || CAN_PANEL_REPLAY(intel_dp))
> > +		return;
> > +
> > +	if (_compute_alpm_params(intel_dp, crtc_state)) {
> > +		context_latency = adjusted_mode->crtc_vblank_start -
> adjusted_mode->crtc_vdisplay;
> > +		guardband = adjusted_mode->crtc_vtotal - adjusted_mode-
> >crtc_vdisplay - context_latency;
> > +		first_sdp_position = adjusted_mode->crtc_vtotal -
> adjusted_mode->crtc_vsync_start;
> > +		auxless_alpm =
> intel_dp_get_aux_less_alpm_status(intel_dp);
> > +		if (auxless_alpm)
> > +			waketime_in_lines = intel_dp-
> >alpm_parameters.io_wake_lines;
> > +		else
> > +			waketime_in_lines = intel_dp-
> >alpm_parameters.aux_less_wake_lines;
> > +
> > +		if ((context_latency + guardband) > (first_sdp_position +
> waketime_in_lines))
> > +			intel_dp->lobf_supported = true;
> > +	}
> > +}
> > +
> >  void intel_psr_get_config(struct intel_encoder *encoder,
> >  			  struct intel_crtc_state *pipe_config)  { diff --git
> > a/drivers/gpu/drm/i915/display/intel_psr.h
> > b/drivers/gpu/drm/i915/display/intel_psr.h
> > index cde781df84d5..4bb77295288f 100644
> > --- a/drivers/gpu/drm/i915/display/intel_psr.h
> > +++ b/drivers/gpu/drm/i915/display/intel_psr.h
> > @@ -40,6 +40,9 @@ void intel_psr_init(struct intel_dp *intel_dp);
> > void intel_psr_compute_config(struct intel_dp *intel_dp,
> >  			      struct intel_crtc_state *crtc_state,
> >  			      struct drm_connector_state *conn_state);
> > +void intel_psr_lobf_compute_config(struct intel_dp *intel_dp,
> > +				   struct intel_crtc_state *crtc_state,
> > +				   struct drm_connector_state *conn_state);
> >  void intel_psr_get_config(struct intel_encoder *encoder,
> >  			  struct intel_crtc_state *pipe_config);  void
> > intel_psr_irq_handler(struct intel_dp *intel_dp, u32 psr_iir);
> 
> --
> Jani Nikula, Intel
Hogander, Jouni March 8, 2024, 1:21 p.m. UTC | #3
On Mon, 2024-03-04 at 13:13 +0530, Animesh Manna wrote:
> Link Off Between Active Frames, is a new feature for eDP
> that allows the panel to go to lower power state after
> transmission of data. This is a feature on top of ALPM, AS SDP.
> Add compute config during atomic-check phase.
> 
> Signed-off-by: Animesh Manna <animesh.manna@intel.com>
> ---
>  .../drm/i915/display/intel_display_types.h    |  3 ++
>  drivers/gpu/drm/i915/display/intel_dp.c       |  1 +
>  drivers/gpu/drm/i915/display/intel_psr.c      | 45
> +++++++++++++++++++
>  drivers/gpu/drm/i915/display/intel_psr.h      |  3 ++
>  4 files changed, 52 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> b/drivers/gpu/drm/i915/display/intel_display_types.h
> index d473d8dca90a..4d2161eeb686 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -1851,6 +1851,9 @@ struct intel_dp {
>                 u8 silence_period_sym_clocks;
>                 u8 lfps_half_cycle_num_of_syms;
>         } alpm_parameters;
> +
> +       /* LOBF flags*/
> +       bool lobf_supported;
>  };
>  
>  enum lspcon_vendor {
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> b/drivers/gpu/drm/i915/display/intel_dp.c
> index 8304ef912767..e34b70d88b9a 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -2979,6 +2979,7 @@ intel_dp_compute_config(struct intel_encoder
> *encoder,
>         intel_vrr_compute_config(pipe_config, conn_state);
>         intel_dp_compute_as_sdp(intel_dp, pipe_config, conn_state);
>         intel_psr_compute_config(intel_dp, pipe_config, conn_state);
> +       intel_psr_lobf_compute_config(intel_dp, pipe_config,
> conn_state);
>         intel_dp_drrs_compute_config(connector, pipe_config,
> link_bpp_x16);
>         intel_dp_compute_vsc_sdp(intel_dp, pipe_config, conn_state);
>         intel_dp_compute_hdr_metadata_infoframe_sdp(intel_dp,
> pipe_config, conn_state);
> diff --git a/drivers/gpu/drm/i915/display/intel_psr.c
> b/drivers/gpu/drm/i915/display/intel_psr.c
> index 4adcddba69c1..c08bffc2921a 100644
> --- a/drivers/gpu/drm/i915/display/intel_psr.c
> +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> @@ -436,6 +436,16 @@ static bool intel_dp_get_alpm_status(struct
> intel_dp *intel_dp)
>         return alpm_caps & DP_ALPM_CAP;
>  }
>  
> +static bool intel_dp_get_aux_less_alpm_status(struct intel_dp
> *intel_dp)
> +{
> +       u8 alpm_caps = 0;
> +
> +       if (drm_dp_dpcd_readb(&intel_dp->aux, DP_RECEIVER_ALPM_CAP,
> +                             &alpm_caps) != 1)
> +               return false;
> +       return alpm_caps & DP_ALPM_AUX_LESS_CAP;
> +}
> +
>  static u8 intel_dp_get_sink_sync_latency(struct intel_dp *intel_dp)
>  {
>         struct drm_i915_private *i915 = dp_to_i915(intel_dp);
> @@ -1569,6 +1579,41 @@ void intel_psr_compute_config(struct intel_dp
> *intel_dp,
>         crtc_state->has_psr2 = intel_psr2_config_valid(intel_dp,
> crtc_state);
>  }
>  
> +void intel_psr_lobf_compute_config(struct intel_dp *intel_dp,
> +                              struct intel_crtc_state *crtc_state,
> +                              struct drm_connector_state

I think this could rather be intel_alpm_compute_config which would
compute alpm parameters including enable for alpm, aux less and lobf.

> *conn_state)
> +{
> +       struct drm_display_mode *adjusted_mode = &crtc_state-
> >hw.adjusted_mode;
> +       int waketime_in_lines, first_sdp_position;
> +       int context_latency, guardband;
> +       bool auxless_alpm;
> +
> +       intel_dp->lobf_supported = false;
> +
> +       if (!intel_dp_is_edp(intel_dp))
> +               return;
> +
> +       if (!intel_dp_as_sdp_supported(intel_dp))
> +               return;
> +
> +       if (CAN_PSR(intel_dp) || CAN_PANEL_REPLAY(intel_dp))
> +               return;

Maybe this should check crtc_state->has_psr2 and crtc_state-
>has_panel_replay ?

BR,

Jouni Högander

> +
> +       if (_compute_alpm_params(intel_dp, crtc_state)) {
> +               context_latency = adjusted_mode->crtc_vblank_start -
> adjusted_mode->crtc_vdisplay;
> +               guardband = adjusted_mode->crtc_vtotal -
> adjusted_mode->crtc_vdisplay - context_latency;
> +               first_sdp_position = adjusted_mode->crtc_vtotal -
> adjusted_mode->crtc_vsync_start;
> +               auxless_alpm =
> intel_dp_get_aux_less_alpm_status(intel_dp);
> +               if (auxless_alpm)
> +                       waketime_in_lines = intel_dp-
> >alpm_parameters.io_wake_lines;
> +               else
> +                       waketime_in_lines = intel_dp-
> >alpm_parameters.aux_less_wake_lines;
> +
> +               if ((context_latency + guardband) >
> (first_sdp_position + waketime_in_lines))
> +                       intel_dp->lobf_supported = true;
> +       }
> +}
> +
>  void intel_psr_get_config(struct intel_encoder *encoder,
>                           struct intel_crtc_state *pipe_config)
>  {
> diff --git a/drivers/gpu/drm/i915/display/intel_psr.h
> b/drivers/gpu/drm/i915/display/intel_psr.h
> index cde781df84d5..4bb77295288f 100644
> --- a/drivers/gpu/drm/i915/display/intel_psr.h
> +++ b/drivers/gpu/drm/i915/display/intel_psr.h
> @@ -40,6 +40,9 @@ void intel_psr_init(struct intel_dp *intel_dp);
>  void intel_psr_compute_config(struct intel_dp *intel_dp,
>                               struct intel_crtc_state *crtc_state,
>                               struct drm_connector_state
> *conn_state);
> +void intel_psr_lobf_compute_config(struct intel_dp *intel_dp,
> +                                  struct intel_crtc_state
> *crtc_state,
> +                                  struct drm_connector_state
> *conn_state);
>  void intel_psr_get_config(struct intel_encoder *encoder,
>                           struct intel_crtc_state *pipe_config);
>  void intel_psr_irq_handler(struct intel_dp *intel_dp, u32 psr_iir);
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index d473d8dca90a..4d2161eeb686 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1851,6 +1851,9 @@  struct intel_dp {
 		u8 silence_period_sym_clocks;
 		u8 lfps_half_cycle_num_of_syms;
 	} alpm_parameters;
+
+	/* LOBF flags*/
+	bool lobf_supported;
 };
 
 enum lspcon_vendor {
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 8304ef912767..e34b70d88b9a 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -2979,6 +2979,7 @@  intel_dp_compute_config(struct intel_encoder *encoder,
 	intel_vrr_compute_config(pipe_config, conn_state);
 	intel_dp_compute_as_sdp(intel_dp, pipe_config, conn_state);
 	intel_psr_compute_config(intel_dp, pipe_config, conn_state);
+	intel_psr_lobf_compute_config(intel_dp, pipe_config, conn_state);
 	intel_dp_drrs_compute_config(connector, pipe_config, link_bpp_x16);
 	intel_dp_compute_vsc_sdp(intel_dp, pipe_config, conn_state);
 	intel_dp_compute_hdr_metadata_infoframe_sdp(intel_dp, pipe_config, conn_state);
diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index 4adcddba69c1..c08bffc2921a 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -436,6 +436,16 @@  static bool intel_dp_get_alpm_status(struct intel_dp *intel_dp)
 	return alpm_caps & DP_ALPM_CAP;
 }
 
+static bool intel_dp_get_aux_less_alpm_status(struct intel_dp *intel_dp)
+{
+	u8 alpm_caps = 0;
+
+	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_RECEIVER_ALPM_CAP,
+			      &alpm_caps) != 1)
+		return false;
+	return alpm_caps & DP_ALPM_AUX_LESS_CAP;
+}
+
 static u8 intel_dp_get_sink_sync_latency(struct intel_dp *intel_dp)
 {
 	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
@@ -1569,6 +1579,41 @@  void intel_psr_compute_config(struct intel_dp *intel_dp,
 	crtc_state->has_psr2 = intel_psr2_config_valid(intel_dp, crtc_state);
 }
 
+void intel_psr_lobf_compute_config(struct intel_dp *intel_dp,
+			       struct intel_crtc_state *crtc_state,
+			       struct drm_connector_state *conn_state)
+{
+	struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
+	int waketime_in_lines, first_sdp_position;
+	int context_latency, guardband;
+	bool auxless_alpm;
+
+	intel_dp->lobf_supported = false;
+
+	if (!intel_dp_is_edp(intel_dp))
+		return;
+
+	if (!intel_dp_as_sdp_supported(intel_dp))
+		return;
+
+	if (CAN_PSR(intel_dp) || CAN_PANEL_REPLAY(intel_dp))
+		return;
+
+	if (_compute_alpm_params(intel_dp, crtc_state)) {
+		context_latency = adjusted_mode->crtc_vblank_start - adjusted_mode->crtc_vdisplay;
+		guardband = adjusted_mode->crtc_vtotal - adjusted_mode->crtc_vdisplay - context_latency;
+		first_sdp_position = adjusted_mode->crtc_vtotal - adjusted_mode->crtc_vsync_start;
+		auxless_alpm = intel_dp_get_aux_less_alpm_status(intel_dp);
+		if (auxless_alpm)
+			waketime_in_lines = intel_dp->alpm_parameters.io_wake_lines;
+		else
+			waketime_in_lines = intel_dp->alpm_parameters.aux_less_wake_lines;
+
+		if ((context_latency + guardband) > (first_sdp_position + waketime_in_lines))
+			intel_dp->lobf_supported = true;
+	}
+}
+
 void intel_psr_get_config(struct intel_encoder *encoder,
 			  struct intel_crtc_state *pipe_config)
 {
diff --git a/drivers/gpu/drm/i915/display/intel_psr.h b/drivers/gpu/drm/i915/display/intel_psr.h
index cde781df84d5..4bb77295288f 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.h
+++ b/drivers/gpu/drm/i915/display/intel_psr.h
@@ -40,6 +40,9 @@  void intel_psr_init(struct intel_dp *intel_dp);
 void intel_psr_compute_config(struct intel_dp *intel_dp,
 			      struct intel_crtc_state *crtc_state,
 			      struct drm_connector_state *conn_state);
+void intel_psr_lobf_compute_config(struct intel_dp *intel_dp,
+				   struct intel_crtc_state *crtc_state,
+				   struct drm_connector_state *conn_state);
 void intel_psr_get_config(struct intel_encoder *encoder,
 			  struct intel_crtc_state *pipe_config);
 void intel_psr_irq_handler(struct intel_dp *intel_dp, u32 psr_iir);