[Intel-gfx] [PATCH v4 5/6] drm/i915/display: Check if pipe fastset is allowed by external dependencies

Souza, Jose jose.souza at intel.com
Wed Dec 18 20:33:28 UTC 2019


On Wed, 2019-12-18 at 22:26 +0200, Ville Syrjälä wrote:
> On Wed, Dec 18, 2019 at 08:19:15PM +0000, Souza, Jose wrote:
> > On Wed, 2019-12-18 at 21:39 +0200, Ville Syrjälä wrote:
> > > On Wed, Dec 18, 2019 at 10:59:09AM -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()
> > > > 
> > > > 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>
> > > > Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> > > > ---
> > > >  drivers/gpu/drm/i915/display/intel_display.c | 53
> > > > +++++++++++++++-
> > > > ----
> > > >  drivers/gpu/drm/i915/display/intel_dp_mst.c  | 14 ++++++
> > > >  drivers/gpu/drm/i915/display/intel_dp_mst.h  |  3 ++
> > > >  3 files 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 a4f252d05b37..2a406891567b 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > > > @@ -13903,19 +13903,6 @@ 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,
> > > > @@ -14083,6 +14070,46 @@ static int intel_atomic_check(struct
> > > > drm_device *dev,
> > > >  			any_ms = true;
> > > >  	}
> > > >  
> > > > +	/**
> > > > +	 * 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
> > > > (!intel_dp_mst_is_slave_trans(new_crtc_state) ||
> > > > +		    needs_modeset(new_crtc_state))
> > > > +			continue;
> > > > +
> > > > +		if
> > > > (intel_dp_mst_master_trans_needs_modeset(state,
> > > > master)) {
> > > 
> > > I think this has the loops the opposite way of what I was
> > > thinking,
> > > but should work fine I think... OK. I'm convinced your way is in
> > > fact
> > > better.
> > > 
> > > > +			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 (needs_modeset(new_crtc_state))
> > > > +			continue;
> > > 
> > > I suppose there isn't any way we should have crtcs in the state
> > > that
> > > neither have update_pipe or needs_modeset flagged here. Could
> > > maybe
> > > WARN_ON(!update_pipe) here if we're being paranoid.
> > 
> > Adding the WARN_ON
> > 
> > > > +
> > > > +		/*
> > > > +		 * 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 a bit unhappy having this state copy inlined in
> > > intel_atomic_check().
> > > 
> > > > +	}
> > > > +
> > > >  	if (any_ms && !check_digital_port_conflicts(state)) {
> > > >  		DRM_DEBUG_KMS("rejecting conflicting digital
> > > > port
> > > > configuration\n");
> > > >  		ret = EINVAL;
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > > > b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > > > index efd14b0b507b..4aba1d702a83 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > > > @@ -854,3 +854,17 @@ bool intel_dp_mst_is_slave_trans(const
> > > > struct
> > > > intel_crtc_state *crtc_state)
> > > >  	return crtc_state->mst_master_transcoder !=
> > > > INVALID_TRANSCODER
> > > > &&
> > > >  	       crtc_state->mst_master_transcoder != crtc_state-
> > > > > cpu_transcoder;
> > > >  }
> > > > +
> > > > +bool intel_dp_mst_master_trans_needs_modeset(struct
> > > > intel_atomic_state *state,
> > > > +					     enum transcoder
> > > > master)
> > > 
> > > Are we going to need this elsewhere? Or be static in
> > > intel_display.c?
> > > Not that people are 100% happy of stuffing everything in there.
> > 
> > Not needed elsewhere, I'm also trying to not put more stuff in
> > intel_display.c.
> > 
> > > > +{
> > > > +	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->mst_master_transcoder ==
> > > > master)
> > > 
> > > So we need to modeset everything when either the master or any
> > > other slave wants to modeset? That is, we can't just modeset
> > > slaves
> > > independently and only force the modesets for all slaves if the
> > > master
> > > needs a modeset?
> > 
> > If a slave needs a modeset we don't need to do a modeset in master
> > or
> > in other slaves.
> > 
> > This is doing independent modeset in slaves and forcing modeset to
> > all
> > slaves when master needs as modeset.
> 
> If you just wanted to check if the master needs a modeset then
> shouldn't
> it just compare crtc_state->cpu_transcoder == master?

Good catch, thanks. 

> 
> And in that case it's not at all MST specific and we could just call
> it
> intel_cpu_transcoder_needs_modeset() or something.

That is true, moving to intel_display then.

> 
> > > > +			return
> > > > drm_atomic_crtc_needs_modeset(&new_crtc_state->uapi);
> > > > +
> > > > +	return false;
> > > > +}
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.h
> > > > b/drivers/gpu/drm/i915/display/intel_dp_mst.h
> > > > index 854724f68f09..72cb486f32ab 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_dp_mst.h
> > > > +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.h
> > > > @@ -8,6 +8,7 @@
> > > >  
> > > >  #include <linux/types.h>
> > > >  
> > > > +struct intel_atomic_state;
> > > >  struct intel_digital_port;
> > > >  struct intel_crtc_state;
> > > >  
> > > > @@ -16,5 +17,7 @@ void intel_dp_mst_encoder_cleanup(struct
> > > > intel_digital_port *intel_dig_port);
> > > >  int intel_dp_mst_encoder_active_links(struct
> > > > intel_digital_port
> > > > *intel_dig_port);
> > > >  bool intel_dp_mst_is_master_trans(const struct
> > > > intel_crtc_state
> > > > *crtc_state);
> > > >  bool intel_dp_mst_is_slave_trans(const struct intel_crtc_state
> > > > *crtc_state);
> > > > +bool intel_dp_mst_master_trans_needs_modeset(struct
> > > > intel_atomic_state *state,
> > > > +					     enum transcoder
> > > > master);
> > > >  
> > > >  #endif /* __INTEL_DP_MST_H__ */
> > > > -- 
> > > > 2.24.1


More information about the Intel-gfx mailing list