[Intel-gfx] [PATCH v5 6/7] drm/i915/display: Check if pipe fastset is allowed by external dependencies

[Souza, Jose]

On Fri, 2019-12-20 at 18:04 +0200, Ville Syrjälä wrote:
> On Fri, Dec 20, 2019 at 07:29:53AM -0800, José Roberto de Souza
> wrote:
> > Check if fastset is allowed by external dependencies like other
> > pipes
> > and transcoders.
> > 
> > Right now this patch only forces a fullmodeset in MST slaves of MST
> > masters that needs a fullmodeset but it will be needed for port
> > sync
> > as well.
> > 
> > v3:
> > - moved handling to intel_atomic_check() this way is guarantee that
> > all pipes will have its state computed
> > 
> > v4:
> > - added a function to return if MST master neeeds modeset to simply
> > code in intel_atomic_check()
> > 
> > v5:
> > - fixed and moved code to check if MST master needs a modeset
> > 
> > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > Cc: Lucas De Marchi <lucas.demarchi at intel.com>
> > Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> > Cc: Manasi Navare <manasi.d.navare at intel.com>
> > Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_display.c | 70
> > ++++++++++++++++----
> >  1 file changed, 57 insertions(+), 13 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> > b/drivers/gpu/drm/i915/display/intel_display.c
> > index 24841dde490b..11f2c13ec23e 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > @@ -13909,19 +13909,6 @@ static void intel_crtc_check_fastset(const
> > struct intel_crtc_state *old_crtc_sta
> >  
> >  	new_crtc_state->uapi.mode_changed = false;
> >  	new_crtc_state->update_pipe = true;
> > -
> > -	/*
> > -	 * If we're not doing the full modeset we want to
> > -	 * keep the current M/N values as they may be
> > -	 * sufficiently different to the computed values
> > -	 * to cause problems.
> > -	 *
> > -	 * FIXME: should really copy more fuzzy state here
> > -	 */
> > -	new_crtc_state->fdi_m_n = old_crtc_state->fdi_m_n;
> > -	new_crtc_state->dp_m_n = old_crtc_state->dp_m_n;
> > -	new_crtc_state->dp_m2_n2 = old_crtc_state->dp_m2_n2;
> > -	new_crtc_state->has_drrs = old_crtc_state->has_drrs;
> >  }
> >  
> >  static int intel_crtc_add_planes_to_state(struct
> > intel_atomic_state *state,
> > @@ -14032,6 +14019,20 @@ static int intel_atomic_check_crtcs(struct
> > intel_atomic_state *state)
> >  	return 0;
> >  }
> >  
> > +static bool intel_cpu_transcoder_needs_modeset(struct
> > intel_atomic_state *state,
> > +					       enum transcoder
> > transcoder)
> > +{
> > +	struct intel_crtc_state *new_crtc_state;
> > +	struct intel_crtc *crtc;
> > +	int i;
> > +
> > +	for_each_new_intel_crtc_in_state(state, crtc, new_crtc_state,
> > i)
> > +		if (new_crtc_state->cpu_transcoder == transcoder)
> > +			return needs_modeset(new_crtc_state);
> > +
> > +	return false;
> > +}
> 
> I would highly recommend splitting this patch into two before pushing
> so that the check vs. copy split goes in first, then the MST thing on
> top. That way if we have to revert either MST or port sync then at
> least we keep this part and won't break the other feature in the
> process.

okay, doing that

> 
> > +
> >  /**
> >   * intel_atomic_check - validate state object
> >   * @dev: drm device
> > @@ -14089,6 +14090,49 @@ static int intel_atomic_check(struct
> > drm_device *dev,
> >  			any_ms = true;
> >  	}
> 
> Was going to say this any_ms thing has to move, but I guess not
> really
> since the below loop won't do anything unless we still have at least
> one crtc needing a modeset. Probably should move it, but can be done
> later.

Okay

> 
> >  
> > +	/**
> > +	 * Check if fastset is allowed by external dependencies like
> > other
> > +	 * pipes and transcoders.
> > +	 *
> > +	 * Right now it only forces a fullmodeset when the MST master
> > +	 * transcoder did not changed but the pipe of the master
> > transcoder
> > +	 * needs a fullmodeset so all slaves also needs to do a
> > fullmodeset.
> > +	 */
> > +	for_each_new_intel_crtc_in_state(state, crtc, new_crtc_state,
> > i) {
> > +		enum transcoder master = new_crtc_state-
> > >mst_master_transcoder;
> > +
> > +		if (!new_crtc_state->uapi.enable ||
> 
> These uapi.enable checks seem fishy. Should at least be hw.enable
> since
> we're past .compute_config() stage already.

Okay

> 
> > +		    !intel_dp_mst_is_slave_trans(new_crtc_state) ||
> > +		    needs_modeset(new_crtc_state))
> > +			continue;
> > +
> > +		if (intel_cpu_transcoder_needs_modeset(state, master))
> > {
> > +			new_crtc_state->uapi.mode_changed = true;
> > +			new_crtc_state->update_pipe = false;
> > +		}
> > +	}
> > +
> > +	for_each_oldnew_intel_crtc_in_state(state, crtc,
> > old_crtc_state,
> > +					    new_crtc_state, i) {
> > +		if (!new_crtc_state->uapi.enable ||
> > +		    needs_modeset(new_crtc_state) ||
> > +		    !new_crtc_state->update_pipe)
> > +			continue;
> > +
> > +		/*
> > +		 * If we're not doing the full modeset we want to
> > +		 * keep the current M/N values as they may be
> > +		 * sufficiently different to the computed values
> > +		 * to cause problems.
> > +		 *
> > +		 * FIXME: should really copy more fuzzy state here
> > +		 */
> > +		new_crtc_state->fdi_m_n = old_crtc_state->fdi_m_n;
> > +		new_crtc_state->dp_m_n = old_crtc_state->dp_m_n;
> > +		new_crtc_state->dp_m2_n2 = old_crtc_state->dp_m2_n2;
> > +		new_crtc_state->has_drrs = old_crtc_state->has_drrs;
> 
> Still sad.


Any suggestion how to fix this? I can work on this after this MST fire.

> 
> > +	}
> > +
> >  	if (any_ms && !check_digital_port_conflicts(state)) {
> >  		DRM_DEBUG_KMS("rejecting conflicting digital port
> > configuration\n");
> >  		ret = EINVAL;
> > -- 
> > 2.24.1