[PATCH] drm/i915/psr: Implement WA to help reach PC10

Kandpal, Suraj suraj.kandpal at intel.com
Mon Nov 4 09:01:39 UTC 2024



> -----Original Message-----
> From: Hogander, Jouni <jouni.hogander at intel.com>
> Sent: Wednesday, October 23, 2024 3:58 PM
> To: Kandpal, Suraj <suraj.kandpal at intel.com>; intel-xe at lists.freedesktop.org
> Cc: Shankar, Uma <uma.shankar at intel.com>; Nikula, Jani
> <jani.nikula at intel.com>
> Subject: Re: [PATCH] drm/i915/psr: Implement WA to help reach PC10
> 
> On Thu, 2024-10-17 at 13:25 +0530, Suraj Kandpal wrote:
> > To reach PC10 when PKG_C_LATENCY is configure we must do the following
> > things
> > 1) Enter PSR1 only when delayed_vblank < 6 lines and DC5 can be
> > entered
> > 2) Allow PSR2 deep sleep when DC5 can be entered
> > 3) DC5 can be entered when all transocoder have either PSR1, PSR2 or
> > eDP 1.5 PR ALPM enabled and VBI is disabled and flips and pushes are
> > not happening.
> >
> > --v2
> > -Add debug prints
> >
> > --v3
> > -use crtc as variable name for intel_crtc [Jani] -use encoder as
> > variable name for intel_encoder [Jani] -No changes in intel_dp in
> > compute_config_late [Jani]
> >
> > WA: 22019444797
> > Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_ddi.c      |   3 +
> >  .../drm/i915/display/intel_display_types.h    |   6 +
> >  drivers/gpu/drm/i915/display/intel_psr.c      | 131
> > +++++++++++++++++-
> >  drivers/gpu/drm/i915/display/intel_psr.h      |   2 +
> >  4 files changed, 141 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c
> > b/drivers/gpu/drm/i915/display/intel_ddi.c
> > index fe1ded6707f9..cbd71c136c8d 100644
> > --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> > +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> > @@ -4368,6 +4368,9 @@ static int intel_ddi_compute_config_late(struct
> > intel_encoder *encoder,
> >                         port_sync_transcoders & ~BIT(crtc_state-
> > >cpu_transcoder);
> >         }
> >
> > +       if (intel_encoder_is_dp(encoder))
> > +               intel_psr_compute_config_late(encoder, crtc_state);
> > +
> 
> I'm wondering if this is right place to add this. I see e.g.
> intel_vrr_compute_config_late being called from
> intel_display::intel_modeset_pipe_config_late. Is that any better? Or should
> we actually now add intel_dp_compute_config_late and move

So from what I can see keeping this in intel_ddi_compute_config_late makes more sense
Since intel_vrr_compute_config_late does not need encoder loop which we need as we need to make sure
Encoder is dp encoder also intel_ddi_encoder_compute_config gets called from encoder->compute_config_late which
Lets it get called from intel_modeset_pipe_config_late.
We would anyways have to make a connector loop if we end up calling intel_psr_compute_config_late in intel_modeset_pipe_config_late

Regards,
Suraj Kandpal

> intel_vrr_compute_config_late there and add this call to
> intel_psr_compute_config_later there as well. Maybe Jani could comment
> this?
> 

@Golani, Mitulkumar Ajitkumar
> BR,
> 
> Jouni Högander
> 
> >         return 0;
> >  }
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> > b/drivers/gpu/drm/i915/display/intel_display_types.h
> > index 2bb1fa64da2f..c980f21a192d 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > @@ -1089,6 +1089,9 @@ struct intel_crtc_state {
> >         bool req_psr2_sdp_prior_scanline;
> >         bool has_panel_replay;
> >         bool wm_level_disabled;
> > +       bool is_wa_delayed_vblank_limit;
> > +       bool is_dpkgc_configured;
> > +       bool is_dc5_entry_possible;
> >         u32 dc3co_exitline;
> >         u16 su_y_granularity;
> >
> > @@ -1587,6 +1590,9 @@ struct intel_psr {
> >  #define I915_PSR_DEBUG_PANEL_REPLAY_DISABLE    0x40
> >
> >         u32 debug;
> > +       bool is_dpkgc_configured;
> > +       bool is_dc5_entry_possible;
> > +       bool is_wa_delayed_vblank_limit;
> >         bool sink_support;
> >         bool source_support;
> >         bool enabled;
> > diff --git a/drivers/gpu/drm/i915/display/intel_psr.c
> > b/drivers/gpu/drm/i915/display/intel_psr.c
> > index 3b20325b3f6a..9f6dcac64dc9 100644
> > --- a/drivers/gpu/drm/i915/display/intel_psr.c
> > +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> > @@ -26,6 +26,7 @@
> >  #include <drm/drm_atomic_helper.h>
> >  #include <drm/drm_damage_helper.h>
> >  #include <drm/drm_debugfs.h>
> > +#include <drm/drm_vblank.h>
> >
> >  #include "i915_drv.h"
> >  #include "i915_reg.h"
> > @@ -896,6 +897,81 @@ static u8 psr_compute_idle_frames(struct intel_dp
> > *intel_dp)
> >         return idle_frames;
> >  }
> >
> > +static bool
> > +intel_psr_check_wa_delayed_vblank(const struct drm_display_mode
> > *adjusted_mode)
> > +{
> > +       return (adjusted_mode->crtc_vblank_start - adjusted_mode-
> > >crtc_vdisplay) >= 6;
> > +}
> > +
> > +/*
> > + * PKG_C_LATENCY is configured only when DISPLAY_VER >= 20 and
> > + * VRR is not enabled
> > + */
> > +static bool intel_psr_is_dpkgc_configured(struct intel_display
> > *display,
> > +                                         struct intel_crtc_state
> > *crtc_state)
> > +{
> > +       if (DISPLAY_VER(display) < 20 || crtc_state->vrr.enable)
> > +               return false;
> > +
> > +       return true;
> > +}
> > +
> > +static bool wa_22019444797_psr1_check(const struct intel_crtc_state
> > *crtc_state,
> > +                                     struct intel_psr *psr) {
> > +       struct intel_display *display = to_intel_display(crtc_state);
> > +
> > +       if (DISPLAY_VER(display) == 20 && psr->is_dpkgc_configured &&
> > +           (psr->is_wa_delayed_vblank_limit || !psr-
> > >is_dc5_entry_possible) &&
> > +          !crtc_state->has_sel_update && !crtc_state-
> > >has_panel_replay) {
> > +               drm_dbg_kms(display->drm,
> > +                           "Wa 22019444797 requirement met PSR1
> > disabled\n");
> > +               return true;
> > +       } else {
> > +               return false;
> > +       }
> > +}
> > +
> > +/*
> > + * DC5 entry is only possible if vblank interrupt is disabled
> > + * and either psr1, psr2, edp 1.5 pr alpm is enabled on all
> > + * enabled encoders.
> > + */
> > +static bool
> > +intel_psr_is_dc5_entry_possible(struct intel_display *display,
> > +                               struct intel_crtc_state *crtc_state) {
> > +       struct intel_crtc *crtc;
> > +
> > +       if ((display->power.domains.target_dc_state &
> > +            DC_STATE_EN_UPTO_DC5_DC6_MASK) == 0)
> > +               return false;
> > +
> > +       if (!crtc_state->has_psr && !crtc_state->has_sel_update &&
> > +           !crtc_state->has_panel_replay)
> > +               return false;
> > +
> > +       for_each_intel_crtc(display->drm, crtc) {
> > +               struct drm_vblank_crtc *vblank;
> > +               struct intel_encoder *encoder;
> > +
> > +               if (!crtc->active)
> > +                       continue;
> > +
> > +               vblank = drm_crtc_vblank_crtc(&crtc->base);
> > +
> > +               if (vblank->enabled)
> > +                       return false;
> > +
> > +               for_each_encoder_on_crtc(display->drm, &crtc->base,
> > encoder)
> > +                       if (encoder->type != INTEL_OUTPUT_EDP ||
> > +                           !CAN_PSR(enc_to_intel_dp(encoder)))
> > +                               return false;
> > +       }
> > +
> > +       return true;
> > +}
> > +
> >  static void hsw_activate_psr1(struct intel_dp *intel_dp)
> >  {
> >         struct intel_display *display = to_intel_display(intel_dp); @@
> > -1008,7 +1084,18 @@ static void hsw_activate_psr2(struct intel_dp
> > *intel_dp)
> >         u32 val = EDP_PSR2_ENABLE;
> >         u32 psr_val = 0;
> >
> > -       val |=
> > EDP_PSR2_IDLE_FRAMES(psr_compute_idle_frames(intel_dp));
> > +       /*
> > +        * Wa_22019444797
> > +        * TODO: Disable idle frames when vblank gets enabled while
> > +        * PSR2 is enabled
> > +        */
> > +       if (DISPLAY_VER(dev_priv) != 20 ||
> > +           !intel_dp->psr.is_dpkgc_configured ||
> > +           intel_dp->psr.is_dc5_entry_possible)
> > +               val |=
> > EDP_PSR2_IDLE_FRAMES(psr_compute_idle_frames(intel_dp));
> > +       else
> > +               drm_dbg_kms(display->drm,
> > +
> >                            "Wa 22019444797 requirement met PSR2 deep
> > sleep disabled\n");
> >         if (DISPLAY_VER(display) < 14 && !IS_ALDERLAKE_P(dev_priv))
> >                 val |= EDP_SU_TRACK_ENABLE; @@ -1686,6 +1773,21 @@
> > void intel_psr_compute_config(struct intel_dp *intel_dp,
> >         crtc_state->has_sel_update =
> > intel_sel_update_config_valid(intel_dp, crtc_state);
> >  }
> >
> > +void intel_psr_compute_config_late(struct intel_encoder *encoder,
> > +                                  struct intel_crtc_state
> > *crtc_state)
> > +{
> > +       struct intel_display *display = to_intel_display(encoder);
> > +
> > +       if (DISPLAY_VER(display) == 20) {
> > +               crtc_state->is_dpkgc_configured =
> > +                       intel_psr_is_dpkgc_configured(display,
> > crtc_state);
> > +               crtc_state->is_dc5_entry_possible =
> > +                       intel_psr_is_dc5_entry_possible(display,
> > crtc_state);
> > +               crtc_state->is_wa_delayed_vblank_limit =
> > +                       intel_psr_check_wa_delayed_vblank(&crtc_state
> > ->hw.adjusted_mode);
> > +       }
> > +}
> > +
> >  void intel_psr_get_config(struct intel_encoder *encoder,
> >                           struct intel_crtc_state *pipe_config)
> >  {
> > @@ -2757,6 +2859,22 @@ int intel_psr2_sel_fetch_update(struct
> > intel_atomic_state *state,
> >         return 0;
> >  }
> >
> > +static void
> > +wa_22019444797_fill_psr_params(const struct intel_crtc_state
> > *crtc_state,
> > +                              struct intel_psr *psr) {
> > +       struct intel_display *display = to_intel_display(crtc_state);
> > +
> > +       if (DISPLAY_VER(display) == 20) {
> > +               psr->is_dpkgc_configured =
> > +                       crtc_state->is_dpkgc_configured;
> > +               psr->is_dc5_entry_possible =
> > +                       crtc_state->is_dc5_entry_possible;
> > +               psr->is_wa_delayed_vblank_limit =
> > +                       crtc_state->is_wa_delayed_vblank_limit;
> > +       }
> > +}
> > +
> >  void intel_psr_pre_plane_update(struct intel_atomic_state *state,
> >                                 struct intel_crtc *crtc)
> >  {
> > @@ -2779,6 +2897,8 @@ void intel_psr_pre_plane_update(struct
> > intel_atomic_state *state,
> >
> >                 mutex_lock(&psr->lock);
> >
> > +               wa_22019444797_fill_psr_params(new_crtc_state, psr);
> > +
> >                 /*
> >                  * Reasons to disable:
> >                  * - PSR disabled in new state @@ -2786,6 +2906,7 @@
> > void intel_psr_pre_plane_update(struct intel_atomic_state *state,
> >                  * - Changing between PSR versions
> >                  * - Region Early Transport changing
> >                  * - Display WA #1136: skl, bxt
> > +                * - Display WA_22019444797
> >                  */
> >                 needs_to_disable |=
> > intel_crtc_needs_modeset(new_crtc_state);
> >                 needs_to_disable |= !new_crtc_state->has_psr; @@
> > -2795,6 +2916,8 @@ void intel_psr_pre_plane_update(struct
> > intel_atomic_state *state,
> >                         psr->su_region_et_enabled;
> >                 needs_to_disable |= DISPLAY_VER(i915) < 11 &&
> >                         new_crtc_state->wm_level_disabled;
> > +               /* TODO: Disable PSR1 when vblank gets enabled while
> > PSR1 is enabled */
> > +               needs_to_disable |=
> > wa_22019444797_psr1_check(new_crtc_state, psr);
> >
> >                 if (psr->enabled && needs_to_disable)
> >                         intel_psr_disable_locked(intel_dp);
> > @@ -2835,6 +2958,12 @@ void intel_psr_post_plane_update(struct
> > intel_atomic_state *state,
> >                 keep_disabled |= DISPLAY_VER(display) < 11 &&
> >                         crtc_state->wm_level_disabled;
> >
> > +               /*
> > +                * Wa_22019444797
> > +                * TODO: Disable PSR1 when vblank gets enabled while
> > PSR1 is enabled
> > +                */
> > +               keep_disabled |=
> > wa_22019444797_psr1_check(crtc_state, psr);
> > +
> >                 if (!psr->enabled && !keep_disabled)
> >                         intel_psr_enable_locked(intel_dp, crtc_state);
> >                 else if (psr->enabled && !crtc_state-
> > >wm_level_disabled)
> > diff --git a/drivers/gpu/drm/i915/display/intel_psr.h
> > b/drivers/gpu/drm/i915/display/intel_psr.h
> > index 5f26f61f82aa..e0fa04952393 100644
> > --- a/drivers/gpu/drm/i915/display/intel_psr.h
> > +++ b/drivers/gpu/drm/i915/display/intel_psr.h
> > @@ -47,6 +47,8 @@ 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_compute_config_late(struct intel_encoder
> > *intel_encoder,
> > +                                  struct intel_crtc_state
> > *crtc_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);



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