[PATCH] drm/i915/psr: Implment WA to help reach PC10
Kandpal, Suraj
suraj.kandpal at intel.com
Mon Sep 2 10:01:31 UTC 2024
> -----Original Message-----
> From: Hogander, Jouni <jouni.hogander at intel.com>
> Sent: Monday, September 2, 2024 3:07 PM
> To: Kandpal, Suraj <suraj.kandpal at intel.com>; intel-
> gfx at lists.freedesktop.org
> Cc: Shankar, Uma <uma.shankar at intel.com>
> Subject: Re: [PATCH] drm/i915/psr: Implment WA to help reach PC10
>
> 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 at intel.com>
> > ---
> > .../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.
Sure will fix in next revision
How about something like check_wa_delayed_vblank()
>
> > +{
> > + 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...
>
How about in the below loop I add a encoder loop that checks if intel_dp_is_edp
If the encoder is active and the psr check is taken care of by checking crtc_state->has_psr ?
Previously I used to check if psr->enabled but since this is now called in psr compute config I only have has_psr to check
If psr can be enabled on that encoder .
Regards,
Suraj Kandpal
> 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 ||
> > + (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,
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