> -----Original Message-----
> From: Cavitt, Jonathan <jonathan.cavitt@xxxxxxxxx>
> Sent: Tuesday, October 1, 2024 8:37 PM
> To: Golani, Mitulkumar Ajitkumar <mitulkumar.ajitkumar.golani@xxxxxxxxx>;
> intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> Cc: Nikula, Jani <jani.nikula@xxxxxxxxx>; Syrjala, Ville <ville.syrjala@xxxxxxxxx>;
> Nautiyal, Ankit K <ankit.k.nautiyal@xxxxxxxxx>; Shankar, Uma
> <uma.shankar@xxxxxxxxx>; Cavitt, Jonathan <jonathan.cavitt@xxxxxxxxx>
> Subject: RE: [PATCH v13 3/3] drm/i915/panelreplay: Panel replay workaround
> with VRR
>
> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of Mitul
> Golani
> Sent: Tuesday, October 1, 2024 6:47 AM
> To: intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> Cc: Nikula, Jani <jani.nikula@xxxxxxxxx>; Syrjala, Ville <ville.syrjala@xxxxxxxxx>;
> Nautiyal, Ankit K <ankit.k.nautiyal@xxxxxxxxx>; Shankar, Uma
> <uma.shankar@xxxxxxxxx>
> Subject: [PATCH v13 3/3] drm/i915/panelreplay: Panel replay workaround with
> VRR
> >
> > From: Animesh Manna <animesh.manna@xxxxxxxxx>
> >
> > Panel Replay VSC SDP not getting sent when VRR is enabled and W1 and
> > W2 are 0. So Program Set Context Latency in TRANS_SET_CONTEXT_LATENCY
> > register to at least a value of 1.
> > The same is applicable for PSR1/PSR2 as well.
> >
> > HSD: 14015406119
> >
> > v1: Initial version.
> > v2: Update timings stored in adjusted_mode struct. [Ville]
> > v3: Add WA in compute_config(). [Ville]
> > v4:
> > - Add DISPLAY_VER() check and improve code comment. [Rodrigo]
> > - Introduce centralized intel_crtc_vblank_delay(). [Ville]
> > v5: Move to crtc_compute_config(). [Ville]
> > v6: Restrict DISPLAY_VER till 14. [Mitul]
> > v7:
> > - Corrected code-comment. [Mitul]
> > - dev_priv local variable removed. [Jani]
> > v8: Introduce late_compute_config() which will take care late
> > vblank-delay adjustment. [Ville]
> > v9: Implementation simplified and split into multiple patches.
> > v10:
> > - Split vrr changes and use struct intel_display in DISPLAY_VER().
> > [Ankit]
> > - Use for_each_new_intel_connector_in_state(). [Jani]
> > v11: Remove loop and use flipline instead of vrr.enable flag. [Ville]
> > v12:
> > - Use intel_Vrr_possible helper.
> > - Correct flag check for flipline.
> >
> > Signed-off-by: Animesh Manna <animesh.manna@xxxxxxxxx>
> > Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@xxxxxxxxx>
>
> I left some notes below, but nothing blocking, so:
> Reviewed-by: Jonathan Cavitt <jonathan.cavitt@xxxxxxxxx>
>
> > ---
> > drivers/gpu/drm/i915/display/intel_display.c | 21
> > ++++++++++++++++++++ drivers/gpu/drm/i915/display/intel_display.h |
> > 1 +
> > 2 files changed, 22 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> > b/drivers/gpu/drm/i915/display/intel_display.c
> > index c59d7bffbf57..a8f846b654e9 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > @@ -2573,6 +2573,8 @@ static int intel_crtc_compute_config(struct
> intel_atomic_state *state,
> > intel_atomic_get_new_crtc_state(state, crtc);
> > int ret;
> >
> > + intel_crtc_adjust_vblank_delay(crtc_state);
>
>
> If the purpose of adjusting the vblank delay is for workaround 14015401596, we
> might want to consider refactoring this into two steps. Specifically, we would
> first separately check if the workaround is needed:
>
> """
> /*
> * wa_14015401596 for display versions 13, 14.
> * Program Set Context Latency in TRANS_SET_CONTEXT_LATENCY register
> * to at least a value of 1 when PSR1/PSR2/Panel Replay is enabled with VRR.
> * Value for TRANS_SET_CONTEXT_LATENCY is calculated by subtracting
> * crtc_vdisplay from crtc_vblank_start, so this workaround is needed when
> * both are equal.
> */
> static bool intel_crtc_needs_wa_14015401596(struct intel_crtc_state
> *crtc_state) {
> struct intel_display *display = to_intel_display(crtc_state);
> struct drm_display_mode *adjusted_mode = &crtc_state-
> >hw.adjusted_mode;
>
> return (intel_vrr_possible(crtc_state) && crtc_state->has_psr &&
> adjusted_mode->crtc_vblank_start == adjusted_mode-
> >crtc_vdisplay &&
> IS_DISPLAY_VER(display, 13, 14));
> }
> """
>
> Then, here, instead of calling intel_crtc_adjust_vblank_delay, we would do this:
>
> """
> if (intel_crtc_needs_wa_14015401596(crtc_state)) {
> struct drm_display_mode *adjusted_mode = &crtc_state-
> >hw.adjusted_mode;
> adjusted_mode->crtc_vblank_start += 1;
> }
> """
>
> I don't think this refactor is strictly necessary, though, so feel free to ignore this.
>
>
> > +
> > ret = intel_dpll_crtc_compute_clock(state, crtc);
> > if (ret)
> > return ret;
> > @@ -3985,6 +3987,25 @@ bool intel_crtc_get_pipe_config(struct
> intel_crtc_state *crtc_state)
> > return true;
> > }
> >
> > +void intel_crtc_adjust_vblank_delay(struct intel_crtc_state
> > +*crtc_state) {
> > + struct intel_display *display = to_intel_display(crtc_state);
> > + struct drm_display_mode *adjusted_mode =
> > +&crtc_state->hw.adjusted_mode;
> > +
> > + /*
> > + * wa_14015401596 for display versions 13, 14.
> > + * Program Set Context Latency in TRANS_SET_CONTEXT_LATENCY
> register
> > + * to at least a value of 1 when PSR1/PSR2/Panel Replay is enabled with
> VRR.
> > + * Value for TRANS_SET_CONTEXT_LATENCY is calculated by
> substracting
>
>
> s/substracting/subtracting
>
>
> > + * crtc_vdisplay from crtc_vblank_start, so incrementing
> crtc_vblank_start
> > + * by 1 if both are equal.
> > + */
> > + if (intel_vrr_possible(crtc_state) && crtc_state->has_psr &&
> > + adjusted_mode->crtc_vblank_start == adjusted_mode->crtc_vdisplay
> &&
> > + IS_DISPLAY_VER(display, 13, 14))
> > + adjusted_mode->crtc_vblank_start += 1; }
> > +
> > int intel_dotclock_calculate(int link_freq,
> > const struct intel_link_m_n *m_n) { diff --git
> > a/drivers/gpu/drm/i915/display/intel_display.h
> > b/drivers/gpu/drm/i915/display/intel_display.h
> > index 1f0fed5ea7bc..e6bd03ef104d 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display.h
> > +++ b/drivers/gpu/drm/i915/display/intel_display.h
> > @@ -446,6 +446,7 @@ u8 _intel_modeset_primary_pipes(const struct
> > intel_crtc_state *crtc_state);
> > u8 _intel_modeset_secondary_pipes(const struct intel_crtc_state
> > *crtc_state); struct intel_crtc *intel_primary_crtc(const struct
> > intel_crtc_state *crtc_state); bool intel_crtc_get_pipe_config(struct
> > intel_crtc_state *crtc_state);
> > +void intel_crtc_adjust_vblank_delay(struct intel_crtc_state
> > +*crtc_state);
>
>
> You may want to make this a static function in intel_display.c. Doing so would
> eliminate the need for the added function declaration in intel_display.h. The
> only caveat is that you would need to move the current definition of this
> function in intel_display.c from where it is now to above
> intel_crtc_compute_config if you wanted to go that route.
> -Jonathan Cavitt
>
Thanks @Cavitt, Jonathan
I agreed to your suggestion related to needs_wa function.
I will address all suggested comments in next revision.
>
> > bool intel_pipe_config_compare(const struct intel_crtc_state
> *current_config,
> > const struct intel_crtc_state *pipe_config,
> > bool fastset);
> > --
> > 2.46.0
> >
> >
