[PATCH v2 4/6] drm/i915/alpm: Add compute config for lobf

Hogander, Jouni jouni.hogander at intel.com
Tue Apr 16 09:06:53 UTC 2024


On Tue, 2024-04-16 at 08:15 +0000, Manna, Animesh wrote:
> 
> 
> > -----Original Message-----
> > From: Hogander, Jouni <jouni.hogander at intel.com>
> > Sent: Monday, April 15, 2024 3:36 PM
> > To: Manna, Animesh <animesh.manna at intel.com>; intel-
> > gfx at lists.freedesktop.org
> > Cc: dri-devel at lists.freedesktop.org; Murthy, Arun R
> > <arun.r.murthy at intel.com>; Nikula, Jani <jani.nikula at intel.com>
> > Subject: Re: [PATCH v2 4/6] drm/i915/alpm: Add compute config for
> > lobf
> > 
> > On Fri, 2024-04-12 at 21:22 +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.
> > > 
> > > v1: RFC version.
> > > v2: Add separate flag for auxless-alpm. [Jani]
> > > 
> > > Signed-off-by: Animesh Manna <animesh.manna at intel.com>
> > > ---
> > >  drivers/gpu/drm/i915/display/intel_alpm.c     | 44
> > > +++++++++++++++++++
> > >  drivers/gpu/drm/i915/display/intel_alpm.h     |  5 +++
> > >  .../drm/i915/display/intel_display_types.h    |  4 ++
> > >  drivers/gpu/drm/i915/display/intel_dp.c       |  5 +++
> > >  4 files changed, 58 insertions(+)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/display/intel_alpm.c
> > > b/drivers/gpu/drm/i915/display/intel_alpm.c
> > > index 13bac3e8c8fa..699f2f051766 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_alpm.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_alpm.c
> > > @@ -11,6 +11,16 @@
> > >  #include "intel_dp_aux.h"
> > >  #include "intel_psr_regs.h"
> > > 
> > > +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; }
> > > +
> > >  /*
> > >   * See Bspec: 71632 for the table
> > >   *
> > > @@ -242,6 +252,40 @@ bool intel_alpm_compute_params(struct
> > > intel_dp
> > > *intel_dp,
> > >         return true;
> > >  }
> > > 
> > > +void intel_alpm_compute_lobf_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;
> > > +
> > > +       intel_dp->lobf_supported = false;
> > > +
> > > +       if (!intel_dp_is_edp(intel_dp))
> > > +               return;
> > > +
> > > +       if (!intel_dp_as_sdp_supported(intel_dp))
> > > +               return;
> > > +
> > > +       if (crtc_state->has_psr2 || crtc_state->has_panel_replay)
> > > +               return;
> > 
> > LOBF is not supported with PSR1? I think checking crtc_state-
> > >has_psr is
> > enough. That covers PSR1/2 and Panel Replay.
> 
> Ok.
> 
> > 
> > > +
> > > +       if (intel_alpm_compute_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;
> > > +               if (intel_dp-
> > > >alpm_parameters.auxless_alpm_supported)
> > > +                       waketime_in_lines = intel_dp-
> > > > alpm_parameters.io_wake_lines;
> > > +               else
> > > +                       waketime_in_lines = intel_dp-
> > > > alpm_parameters.fast_wake_lines;
> > > +
> > > +               if ((context_latency + guardband) >
> > > (first_sdp_position + waketime_in_lines))
> > > +                       intel_dp->lobf_supported = true;
> > > +       }
> > 
> > You are not checking display version here. This is supported only
> > on LNL and
> > onwards.
> 
> Sure will add, thought as-sdp-support will take care, but it has
> display_ver >= 13.
> 
> > 
> > > +}
> > > +
> > >  static void lnl_alpm_configure(struct intel_dp *intel_dp)
> > >  {
> > >         struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> > > diff
> > > --git a/drivers/gpu/drm/i915/display/intel_alpm.h
> > > b/drivers/gpu/drm/i915/display/intel_alpm.h
> > > index c45d078e5a6b..c341d2c2b7f7 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_alpm.h
> > > +++ b/drivers/gpu/drm/i915/display/intel_alpm.h
> > > @@ -10,9 +10,14 @@
> > > 
> > >  struct intel_dp;
> > >  struct intel_crtc_state;
> > > +struct drm_connector_state;
> > > 
> > > +bool intel_dp_get_aux_less_alpm_status(struct intel_dp
> > > *intel_dp);
> > >  bool intel_alpm_compute_params(struct intel_dp *intel_dp,
> > >                                struct intel_crtc_state
> > > *crtc_state);
> > > +void intel_alpm_compute_lobf_config(struct intel_dp *intel_dp,
> > > +                                   struct intel_crtc_state
> > > *crtc_state,
> > > +                                   struct drm_connector_state
> > > *conn_state);
> > >  void intel_alpm_configure(struct intel_dp *intel_dp);
> > > 
> > >  #endif
> > > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > index 73197f014510..6116c383b543 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > @@ -1876,10 +1876,14 @@ struct intel_dp {
> > >                 u8 fast_wake_lines;
> > > 
> > >                 /* LNL and beyond */
> > > +               bool auxless_alpm_supported;
> > >                 u8 check_entry_lines;
> > >                 u8 silence_period_sym_clocks;
> > >                 u8 lfps_half_cycle_num_of_syms;
> > >         } alpm_parameters;
> > > +
> > > +       /* LOBF flags*/
> > > +       bool lobf_supported;
> > 
> > I think having it here and naming like this is misleading. How
> > about
> > intel_crtc_state->has_lobf?
> 
> How about "bool lobf_entry_criteria" ?

My mind is polluted with PSR code: I would have chosen has_lobf. I'm
not against lobf_entry_criteria.

BR,

Jouni Högander

> 
> > 
> > >  };
> > > 
> > >  enum lspcon_vendor {
> > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> > > b/drivers/gpu/drm/i915/display/intel_dp.c
> > > index 163da48bc406..12ec796568d9 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > > @@ -48,6 +48,7 @@
> > >  #include "i915_drv.h"
> > >  #include "i915_irq.h"
> > >  #include "i915_reg.h"
> > > +#include "intel_alpm.h"
> > >  #include "intel_atomic.h"
> > >  #include "intel_audio.h"
> > >  #include "intel_backlight.h"
> > > @@ -3001,6 +3002,7 @@ 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);
> > >         intel_psr_compute_config(intel_dp, pipe_config,
> > > conn_state);
> > > +       intel_alpm_compute_lobf_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);
> > > @@ -6616,6 +6618,9 @@ static bool intel_edp_init_connector(struct
> > > intel_dp *intel_dp,
> > > 
> > >         intel_pps_init_late(intel_dp);
> > > 
> > > +       if (intel_dp_get_aux_less_alpm_status(intel_dp))
> > > +               intel_dp->alpm_parameters.auxless_alpm_supported
> > > =
> > > true;
> > > +
> > 
> > intel_dp->alpm_parameters.auxless_alpm_supported =
> > intel_dp_get_aux_less_alpm_status(intel_dp);
> 
> Ok.
> 
> Regards,
> Animesh
> 
> > 
> > BR,
> > 
> > Jouni Högander
> > 
> > >         return true;
> > > 
> > >  out_vdd_off:
> 



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