[Intel-gfx] [PATCH 2/3] drm/i915: Check timings against hardware maximums

[Chris Wilson]

Quoting Ville Syrjälä (2018-06-15 20:48:49)
> On Fri, Jun 15, 2018 at 07:44:08PM +0100, Chris Wilson wrote:
> > Quoting Ville Syrjala (2018-06-15 18:44:05)
> > > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > 
> > > Validate that all display timings fit within the number of bits
> > > we have in the transcoder timing registers.
> > > 
> > > The limits are:
> > > hsw+:
> > >  4k: vdisplay, vblank_start
> > >  8k: everything else
> > > gen3+:
> > >  4k: h/vdisplay, h/vblank_start
> > >  8k: everything else
> > > gen2:
> > >  2k: h/vdisplay, h/vblank_start
> > >  4k: everything else
> > > 
> > > Also document the fact that the mode_config.max_width/height limits
> > > refer to just the max framebuffer dimensions we support. Which may
> > > be larger than the max hdisplay/vdisplay.
> > 
> > In the ddx, I used them to filter max hdisplay/vdisplay... And
> > completely ignored them wrt to framebuffer.
> 
> Whatever works :)

Yeah, and this doesn't break -intel afaict, since ultimately validation
is done by the kernel and we/the client just keeps on trying something
until it works (or more often until they just give up).
-Chris