Re: [PATCH v3 5/6] drm/i915/psr: Enable ALPM for eDP Panel replay

["Hogander, Jouni" <jouni.hogander@intel.com>]

On Wed, 2024-03-13 at 11:15 +0000, Manna, Animesh wrote:
> 
> 
> > -----Original Message-----
> > From: Hogander, Jouni <jouni.hogander@intel.com>
> > Sent: Wednesday, March 6, 2024 4:15 PM
> > To: intel-gfx@lists.freedesktop.org
> > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>; Manna, Animesh
> > <animesh.manna@intel.com>; Murthy, Arun R
> > <arun.r.murthy@intel.com>;
> > Hogander, Jouni <jouni.hogander@intel.com>
> > Subject: [PATCH v3 5/6] drm/i915/psr: Enable ALPM for eDP Panel
> > replay
> > 
> > Enable ALPM AUX-Less for Panel Replay eDP. Also write all
> > calculated AUX-
> > Less configuration values accordingly.
> > 
> > Bspec: 71477
> > 
> > v3:
> >   - do not use alpm_ctl as uninitialized variable
> > v2:
> >   - do not set AUX-Wake related bits for AUX-Less case
> >   - drop switch to active latency
> >   - add SLEEP_HOLD_TIME_50_SYMBOLS
> >   - add PORT_ALPM_CTL_MAX_PHY_SWING_HOLD
> > 
> > Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_psr.c | 42
> > +++++++++++++++++++++---
> >  1 file changed, 38 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_psr.c
> > b/drivers/gpu/drm/i915/display/intel_psr.c
> > index 738ea623a395..4cd2bad5241f 100644
> > --- a/drivers/gpu/drm/i915/display/intel_psr.c
> > +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> > @@ -1697,14 +1697,39 @@ static void lnl_alpm_configure(struct
> > intel_dp
> > *intel_dp)
> >         struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> >         enum transcoder cpu_transcoder = intel_dp->psr.transcoder;
> >         struct intel_psr *psr = &intel_dp->psr;
> > +       u32 alpm_ctl;
> > 
> >         if (DISPLAY_VER(dev_priv) < 20)
> >                 return;
> > 
> > -       intel_de_write(dev_priv, ALPM_CTL(cpu_transcoder),
> > -                      ALPM_CTL_EXTENDED_FAST_WAKE_ENABLE |
> > -                      ALPM_CTL_ALPM_ENTRY_CHECK(psr-
> > > alpm_parameters.check_entry_lines) |
> > -                      ALPM_CTL_EXTENDED_FAST_WAKE_TIME(psr-
> > > alpm_parameters.fast_wake_lines));
> > +       if (intel_dp->psr.panel_replay_enabled &&
> > intel_dp_is_edp(intel_dp)) {
> > +               alpm_ctl = ALPM_CTL_ALPM_ENABLE |
> > +                       ALPM_CTL_ALPM_AUX_LESS_ENABLE |
> > +
> >         ALPM_CTL_AUX_LESS_SLEEP_HOLD_TIME_50_SYMBOLS;
> > +
> > +               intel_de_write(dev_priv,
> > PORT_ALPM_CTL(cpu_transcoder),
> > +                              PORT_ALPM_CTL_ALPM_AUX_LESS_ENABLE |
> 
> Good to add code-comments why aux-less alpm is enabled without
> checking panel capability.
> 
> Same for below wherever we are setting bit for aux-less alpm.

Ok, I will add these comments.

BR,

Jouni Högander
> 
> Regards,
> Animesh
>  
> > +                             
> > PORT_ALPM_CTL_MAX_PHY_SWING_SETUP(15) |
> > +                              PORT_ALPM_CTL_MAX_PHY_SWING_HOLD(0)
> > |
> > +                              PORT_ALPM_CTL_SILENCE_PERIOD(
> > +                                      psr-
> > > alpm_parameters.silence_period_sym_clocks));
> > +
> > +               intel_de_write(dev_priv,
> > PORT_ALPM_LFPS_CTL(cpu_transcoder),
> > +                             
> > PORT_ALPM_LFPS_CTL_LFPS_CYCLE_COUNT(10) |
> > +
> > PORT_ALPM_LFPS_CTL_LFPS_HALF_CYCLE_DURATION(
> > +                                      psr-
> > > alpm_parameters.lfps_half_cycle_num_of_syms) |
> > +
> > PORT_ALPM_LFPS_CTL_FIRST_LFPS_HALF_CYCLE_DURATION(
> > +                                      psr-
> > > alpm_parameters.lfps_half_cycle_num_of_syms) |
> > +
> > PORT_ALPM_LFPS_CTL_LAST_LFPS_HALF_CYCLE_DURATION(
> > +                                      psr-
> > > alpm_parameters.lfps_half_cycle_num_of_syms));
> > +       } else {
> > +               alpm_ctl = ALPM_CTL_EXTENDED_FAST_WAKE_ENABLE |
> > +                       ALPM_CTL_EXTENDED_FAST_WAKE_TIME(psr-
> > > alpm_parameters.fast_wake_lines);
> > +       }
> > +
> > +       alpm_ctl |=
> > +ALPM_CTL_ALPM_ENTRY_CHECK(psr-
> > > alpm_parameters.check_entry_lines);
> > +
> > +       intel_de_write(dev_priv, ALPM_CTL(cpu_transcoder),
> > alpm_ctl);
> >  }
> > 
> >  static void intel_psr_enable_source(struct intel_dp *intel_dp, @@
> > -1975,6
> > +2000,15 @@ static void intel_psr_disable_locked(struct intel_dp
> > *intel_dp)
> > 
> >         intel_snps_phy_update_psr_power_state(dev_priv, phy,
> > false);
> > 
> > +       if (intel_dp->psr.panel_replay_enabled &&
> > intel_dp_is_edp(intel_dp)) {
> > +               intel_de_rmw(dev_priv, ALPM_CTL(cpu_transcoder),
> > +                            ALPM_CTL_ALPM_ENABLE |
> > +                            ALPM_CTL_ALPM_AUX_LESS_ENABLE, 0);
> > +
> > +               intel_de_rmw(dev_priv,
> > PORT_ALPM_CTL(cpu_transcoder),
> > +                            PORT_ALPM_CTL_ALPM_AUX_LESS_ENABLE,
> > 0);
> > +       }
> > +
> >         /* Disable PSR on Sink */
> >         drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_EN_CFG, 0);
> > 
> > --
> > 2.34.1
>