On Mon, 2024-09-02 at 11:07 +0000, Kandpal, Suraj wrote:
>
>
> > -----Original Message-----
> > From: Hogander, Jouni <jouni.hogander@xxxxxxxxx>
> > Sent: Monday, September 2, 2024 4:32 PM
> > To: Kandpal, Suraj <suraj.kandpal@xxxxxxxxx>; intel-
> > gfx@xxxxxxxxxxxxxxxxxxxxx
> > Cc: Shankar, Uma <uma.shankar@xxxxxxxxx>
> > Subject: Re: [PATCH] drm/i915/psr: Implment WA to help reach PC10
> >
> > On Mon, 2024-09-02 at 10:14 +0000, Kandpal, Suraj wrote:
> > >
> > >
> > > > -----Original Message-----
> > > > From: Hogander, Jouni <jouni.hogander@xxxxxxxxx>
> > > > Sent: Monday, September 2, 2024 3:32 PM
> > > > To: Kandpal, Suraj <suraj.kandpal@xxxxxxxxx>; intel-
> > > > gfx@xxxxxxxxxxxxxxxxxxxxx
> > > > Cc: Shankar, Uma <uma.shankar@xxxxxxxxx>
> > > > Subject: Re: [PATCH] drm/i915/psr: Implment WA to help reach
> > > > PC10
> > > >
> > > > On Mon, 2024-09-02 at 12:37 +0300, Hogander, Jouni wrote:
> > > > > On Mon, 2024-09-02 at 10:32 +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
> > > > > > -Switch condition and do an early return [Jani] -Do some
> > > > > > checks
> > > > > > in compute_config [Jani] -Do not use register reads as a
> > > > > > method
> > > > > > of checking states for DPKGC or delayed vblank [Jani] -Use
> > > > > > another way to see is vblank interrupts are disabled or not
> > > > > > [Jani]
> > > > > >
> > > > > > --v3
> > > > > > -Use has_psr to check if psr can be enabled or not for
> > > > > > dc5_entry
> > > > > > cond [Uma] -Move the dc5 entry computation to
> > > > > > psr_compute_config
> > > > > > [Jouni] -No need to change sequence of enabled and
> > > > > > activate, so
> > > > > > dont make hsw_psr1_activate return anything [Jouni] -Use
> > > > > > has_psr
> > > > > > to stop
> > > > > > psr1 activation [Jouni] -Use lineage no. in WA -Add the
> > > > > > display
> > > > > > ver restrictions for WA
> > > > > >
> > > > > > WA: 22019444797
> > > > > > Signed-off-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx>
> > > > > > ---
> > > > > > .../drm/i915/display/intel_display_types.h | 2 +
> > > > > > drivers/gpu/drm/i915/display/intel_psr.c | 96
> > > > > > ++++++++++++++++++-
> > > > > > 2 files changed, 97 insertions(+), 1 deletion(-)
> > > > > >
> > > > > > diff --git
> > > > > > a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > > > b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > > > index 868ff8976ed9..5395c1ecde7f 100644
> > > > > > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > > > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > > > @@ -1717,6 +1717,8 @@ struct intel_psr {
> > > > > > bool sink_support;
> > > > > > bool source_support;
> > > > > > bool enabled;
> > > > > > + bool is_dpkgc_configured;
> > > > > > + bool is_dc5_entry_possible;
> > > > > > bool paused;
> > > > > > enum pipe pipe;
> > > > > > enum transcoder transcoder; diff --git
> > > > > > a/drivers/gpu/drm/i915/display/intel_psr.c
> > > > > > b/drivers/gpu/drm/i915/display/intel_psr.c
> > > > > > index 257526362b39..1faec76eac32 100644
> > > > > > --- a/drivers/gpu/drm/i915/display/intel_psr.c
> > > > > > +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> > > > > > @@ -870,6 +870,69 @@ static u8
> > > > > > psr_compute_idle_frames(struct
> > > > > > intel_dp *intel_dp)
> > > > > > return idle_frames;
> > > > > > }
> > > > > >
> > > > > > +static bool intel_psr_check_delayed_vblank_limit(struct
> > > > > > intel_crtc_state *crtc_state)
> > > > >
> > > > > You could add some context here in the name. This is somehow
> > > > > telling it's some generic delayed vblank limit while it is
> > > > > actually limit for this workaround.
> > > > >
> > > > > > +{
> > > > > > + struct drm_display_mode *adjusted_mode =
> > > > > > &crtc_state-
> > > > > > > hw.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
> > > > > > drm_i915_private
> > > > > > *i915)
> > > > > > +{
> > > > > > + struct intel_crtc *intel_crtc;
> > > > > > +
> > > > > > + if (DISPLAY_VER(i915) < 20)
> > > > > > + return false;
> > > > > > +
> > > > > > + for_each_intel_crtc(&i915->drm, intel_crtc) {
> > > > > > + struct intel_crtc_state *crtc_state;
> > > > > > +
> > > > > > + if (!intel_crtc->active)
> > > > > > + continue;
> > > > > > +
> > > > > > + crtc_state = intel_crtc->config;
> > > > > > +
> > > > > > + if (crtc_state->vrr.enable)
> > > > > > + return false;
> > > > > > + }
> > > > > > +
> > > > > > + return true;
> > > > > > +}
> > > > > > +
> > > > > > +/*
> > > > > > + * 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 drm_i915_private
> > > > > > *i915,
> > > > > > + struct intel_crtc_state
> > > > > > *crtc_state)
> > > > > > +{
> > > > > > + struct intel_crtc *intel_crtc;
> > > > > > +
> > > > > > + if (!(crtc_state->has_psr || crtc_state-
> > > > > > > has_sel_update))
> > > > > > + return false;
> > > > >
> > > > > Currently this is not returning for DP2.1 PR. This would
> > > > > better
> > > > > match with comment above:
> > > > >
> > > > > if (!crtc_state->has_psr || !intel_dp_is_edp(intel_dp))
> > > > > return false;
> > > > >
> > > > > Still "_all_ enabled encoders" is not handled...
> > > > >
> > > > > BR,
> > > > >
> > > > > Jouni Högander
> > > > >
> > > > > > +
> > > > > > + for_each_intel_crtc(&i915->drm, intel_crtc) {
> > > > > > + struct drm_crtc *crtc = &intel_crtc->base;
> > > > > > + struct drm_vblank_crtc *vblank;
> > > > > > +
> > > > > > + if (!intel_crtc->active)
> > > > > > + continue;
> > > > > > +
> > > > > > + vblank = drm_crtc_vblank_crtc(crtc);
> > > > > > +
> > > > > > + if (vblank->enabled)
> > > > > > + return false;
> > > > > > + }
> > > > > > +
> > > > > > + return true;
> > > > > > +}
> > > > > > +
> > > > > > static void hsw_activate_psr1(struct intel_dp *intel_dp)
> > > > > > {
> > > > > > struct drm_i915_private *dev_priv =
> > > > > > dp_to_i915(intel_dp); @@
> > > > > > -980,7 +1043,11 @@ 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 */
> > > > > > + if (DISPLAY_VER(dev_priv) != 20 ||
> > > >
> > > > I think this is wrong. It will not configure idle frames for
> > > > display
> > > > version other than 20.
> > >
> > > Wouldn’t this configure idle frames for all versions except 20
> > > And if
> > > it is 20 then if dpkgc is configured and dc5 entry is possible
> > > Only
> > > then configure idle frames
> >
> > Yes. My bad. sorry for that. This should be ok for display version
> > != 20.
> > Another thing here. WA description is:
> >
>
> > "When PKG_C_LATENCY is configured (not all 1s), enable PSR2 deep
> > sleep
> > (PSR2_CTL Idle Frames != 0) only when DC5 can be entered."
> >
> > How about case where PKG_C_LATENCY is not configured? Do we need to
> > care about it?
>
> No we do not need to care about that the WA states this is only seen
> when dpkgc is configured
> On lnl
Ok, but you are still applying the WA (i.e. leaving PSR2_CTL[idle
frames] as 0) for case where dpkc is not configured.
BR,
Jouni Högander
>
> Regards,
> Suraj Kandpal
>
> >
> > BR,
> >
> > Jouni Högander
> >
> > >
> > > Regards,
> > > Suraj Kandpal
> > > >
> > > > BR,
> > > >
> > > > Jouni Högander
> > > >
> > > > > > + (intel_dp->psr.is_dpkgc_configured &&
> > > > > > + intel_dp->psr.is_dc5_entry_possible))
> > > > > > + val |=
> > > > > > EDP_PSR2_IDLE_FRAMES(psr_compute_idle_frames(intel_dp));
> > > > > >
> > > > > > if (DISPLAY_VER(dev_priv) < 14 &&
> > > > > > !IS_ALDERLAKE_P(dev_priv))
> > > > > > val |= EDP_SU_TRACK_ENABLE; @@ -1595,6
> > > > > > +1662,32
> > > > > > @@ _panel_replay_compute_config(struct intel_dp *intel_dp,
> > > > > > return true;
> > > > > > }
> > > > > >
> > > > > > +static void wa_22019444797(struct intel_dp *intel_dp,
> > > > > > + struct intel_crtc_state
> > > > > > *crtc_state)
> > > > > > {
> > > > > > + struct drm_i915_private *i915 =
> > > > > > dp_to_i915(intel_dp);
> > > > > > +
> > > > > > + if (DISPLAY_VER(i915) != 20)
> > > > > > + return;
> > > > > > +
> > > > > > + intel_dp->psr.is_dpkgc_configured =
> > > > > > + intel_psr_is_dpkgc_configured(i915);
> > > > > > + intel_dp->psr.is_dc5_entry_possible =
> > > > > > + intel_psr_is_dc5_entry_possible(i915,
> > > > > > crtc_state);
> > > > > > +
> > > > > > + /* PSR2 not handled here. Wa not needed for Panel
> > > > > > Replay */
> > > > > > + if (crtc_state->has_sel_update || crtc_state-
> > > > > > > has_panel_replay)
> > > > > > + return;
> > > > > > +
> > > > > > + if (intel_dp->psr.is_dpkgc_configured &&
> > > > > > +
> > > > > > (intel_psr_check_delayed_vblank_limit(crtc_state)
> > > > > > > >
> > > > > > + intel_dp->psr.is_dc5_entry_possible)) {
> > > > > > + drm_dbg_kms(&i915->drm,
> > > > > > + "PSR1 not enabled as it doesn't
> > > > > > meet
> > > > > > requirements of WA: 22019444797\n");
> > > > > > + crtc_state->has_psr = false;
> > > > > > + }
> > > > > > +}
> > > > > > +
> > > > > > void intel_psr_compute_config(struct intel_dp *intel_dp,
> > > > > > struct intel_crtc_state
> > > > > > *crtc_state,
> > > > > > struct drm_connector_state
> > > > > > *conn_state)
> > > > > > @@ -1641,6 +1734,7 @@ void intel_psr_compute_config(struct
> > > > > > intel_dp *intel_dp,
> > > > > > return;
> > > > > >
> > > > > > crtc_state->has_sel_update =
> > > > > > intel_sel_update_config_valid(intel_dp, crtc_state);
> > > > > > + wa_22019444797(intel_dp, crtc_state);
> > > > > > }
> > > > > >
> > > > > > void intel_psr_get_config(struct intel_encoder *encoder,
> > > > >
> > >
>
