[Intel-gfx] [PATCH] drm/i915: perform scaler_id check for skl+

[Konduru, Chandra]

> > Scaler id is added for skylake to handle its shared scalers.
> > This is not applicable for platforms before SKL. This patch limits
> > the scaler_id check during intel_pipe_config_compare to platforms
> > SKL and above.
> 
> Please add a References: line here with the bug report from mailing lists.
> Also please do a quick query of bugzilla, QA should have hit this too and
> filed it.
> 
> Also please reference the commit that introduce this warning (or the most
> likely one).

Will update and send updated patch with references to commit and mailing list.

> >
> > -	PIPE_CONF_CHECK_I(scaler_state.scaler_id);
> > +	if (INTEL_INFO(dev)->gen >= 9) {
> > +		PIPE_CONF_CHECK_I(scaler_state.scaler_id);
> > +	}
> 
> In general all the state should be left as 0 on platforms that don't
> support it. We only have conditionals for platforms where we compute
> state, but for some hw-specific reason can't always reconstruct it from hw
> state alone. Hence the correct fix would be to make sure that we leave
> scaler_id == 0 in both compute_config and read_hw_state functions for gen
> < 9.	

Working on updated patch leaving scaler_id as 0 for gen<9 and sending soon.