[Intel-gfx] [PATCH 1/3] drm/i915/dp: Make sure all tiled connectors get added to the state with full modeset

[Ville Syrjälä]

On Fri, Dec 13, 2019 at 01:05:48PM -0800, Manasi Navare wrote:
> On Fri, Dec 13, 2019 at 10:05:49PM +0200, Ville Syrjälä wrote:
> > On Wed, Dec 11, 2019 at 01:14:23PM -0800, Manasi Navare wrote:
> > > In case of tiled displays, all the tiles are linke dto each other
> > > for transcoder port sync. So in intel_atomic_check() we need to make
> > > sure that we add all the tiles to the modeset and if one of the
> > > tiles needs a full modeset then mark all other tiles for a full modeset.
> > > 
> > > Suggested-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > Cc: José Roberto de Souza <jose.souza at intel.com>
> > > Bugzilla: https://gitlab.freedesktop.org/drm/intel/issues/5
> > > Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
> > > ---
> > >  drivers/gpu/drm/i915/display/intel_display.c | 78 ++++++++++++++++++++
> > >  1 file changed, 78 insertions(+)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> > > index 803993a01ca7..7263eaa66cda 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > > @@ -14066,6 +14066,80 @@ static int intel_atomic_check_crtcs(struct intel_atomic_state *state)
> > >  	return 0;
> > >  }
> > >  
> > > +static int
> > > +intel_dp_modeset_all_tiles(struct drm_i915_private *dev_priv,
> > > +			   struct intel_atomic_state *state, int tile_grp_id)
> > > +{
> > > +	struct drm_connector *conn_iter;
> > 'connector'
> 
> Ok
> 
> > > +	struct drm_connector_list_iter conn_list_iter;
> > > +	struct drm_crtc_state *crtc_state;
> > 
> > crtc_state has needlessly wide scope.
> 
> Ok will add it inside the loop
> 
> > 
> > > +
> > > +	drm_connector_list_iter_begin(&dev_priv->drm, &conn_list_iter);
> > > +	drm_for_each_connector_iter(conn_iter, &conn_list_iter) {
> > > +		struct drm_connector_state *conn_iter_state;
> > 
> > 'conn_state' is the most popular name.
> > 
> > > +
> > > +		if (!conn_iter->has_tile)
> > > +			continue;
> > > +		conn_iter_state = drm_atomic_get_connector_state(&state->base,
> > > +								 conn_iter);
> > > +		if (IS_ERR(conn_iter_state)) {
> > > +			drm_connector_list_iter_end(&conn_list_iter);
> > > +			return PTR_ERR(conn_iter_state);
> > > +		}
> > > +
> > > +		if (!conn_iter_state->crtc)
> > > +			continue;
> > > +
> > > +		if (conn_iter->tile_group->id != tile_grp_id)
> > > +			continue;
> > 
> > The tile group check should be part of the same if with the has_tile
> > check.
> 
> Ok yes. So not pass the tile grp id at all just compare with current
> connector's tile_grp_id ?

You still need to pass in the tile_grp_id from the caller's current
connector. What I meant is that you should do 

if (!connector->has_tile || connector->tile_grp != tile_grp)
	continue;

before you do the drm_atomic_get_connector_state(). We don't want to
needlessly add connectors belonging to some other tile group to our
atomic state.

> 
> > 
> > > +
> > > +		crtc_state = drm_atomic_get_crtc_state(&state->base, conn_iter_state->crtc);
> > > +		if (IS_ERR(crtc_state)) {
> > > +			drm_connector_list_iter_end(&conn_list_iter);
> > > +			return PTR_ERR(conn_iter_state);
> > > +		}
> > > +		crtc_state->mode_changed = true;
> > > +	}
> > > +	drm_connector_list_iter_end(&conn_list_iter);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static int
> > > +intel_dp_atomic_trans_port_sync_check(struct drm_i915_private *dev_priv,
> > 
> > Pointless variable. Can be extracted from the atomic state.
> > 
> > > +				      struct intel_atomic_state *state)
> > > +{
> > > +	struct drm_connector *connector;
> > > +	struct drm_crtc_state *crtc_state;
> > > +	struct drm_connector_state *connector_state;
> > > +	int i, ret, tile_grp_id = 0;
> > 
> > tile_grp_id is rather pointless. crtc_state and ret can move into
> > tighter scope. And the next suggestion allows you to kill crtc_state
> > entirely...
> 
> tile_grp_id  is useless because I should just use it from current connector obtained from state?

I just meant that you use that variable exactly once. So instead you can
just directly do:

ret = intel_dp_modeset_all_tiles(state, connector->tile_grp_id);
...



> 
> > 
> > > +
> > > +	if (INTEL_GEN(dev_priv) < 11)
> > > +		return 0;
> > > +
> > > +	/* Is tiled, mark all other tiled CRTCs as needing a modeset */
> > > +	for_each_new_connector_in_state(&state->base, connector, connector_state, i) {
> > > +		if (!connector->has_tile)
> > > +			continue;
> > > +		if (connector_state->crtc &&
> > > +		    tile_grp_id != connector->tile_group->id) {
> > > +			crtc_state = drm_atomic_get_new_crtc_state(&state->base,
> > > +								   connector_state->crtc);
> > > +			if (!drm_atomic_crtc_needs_modeset(crtc_state))
> > > +				continue;
> > 
> > This should to be able to be shortened to just intel_connector_needs_modeset().
> 
> Ok will use that instead.
> 
> > 
> > > +
> > > +			tile_grp_id = connector->tile_group->id;
> > > +		} else
> > > +			continue;
> > > +
> > > +		ret = intel_dp_modeset_all_tiles(dev_priv, state, tile_grp_id);
> > > +		if (ret)
> > > +			return ret;
> > > +	}
> > > +
> > > +	return 0;
> > > +}
> > > +
> > >  /**
> > >   * intel_atomic_check - validate state object
> > >   * @dev: drm device
> > > @@ -14093,6 +14167,10 @@ static int intel_atomic_check(struct drm_device *dev,
> > >  	if (ret)
> > >  		goto fail;
> > >  
> > > +	ret = intel_dp_atomic_trans_port_sync_check(dev_priv, state);
> > > +	if (ret)
> > > +		goto fail;
> > 
> > We should probably do this from the connector .atomic_check() hook if
> > Jose is going to do the MST thing that way. But no real problem doing
> > here I think.
> 
> If you dont have a strong preference I will leave it here since Jose's code is not in yet.
> 
> Manasi
> 
> > 
> > > +
> > >  	for_each_oldnew_intel_crtc_in_state(state, crtc, old_crtc_state,
> > >  					    new_crtc_state, i) {
> > >  		if (!needs_modeset(new_crtc_state)) {
> > > -- 
> > > 2.19.1
> > 
> > -- 
> > Ville Syrjälä
> > Intel

-- 
Ville Syrjälä
Intel