[Intel-gfx] [PATCH 0/4] [CFT] interlaced support

[Daniel Vetter]

On Fri, Jan 27, 2012 at 06:43:06PM +0100, Daniel Vetter wrote:
> On Fri, Jan 27, 2012 at 02:25:49PM -0200, Paulo Zanoni wrote:
> > Ok, so I had to look at the Windows registers again...
> > 
> > Your "interlaced" branch had 6 patches. Patch 3 is the only one I
> > changed. Here is my version:
> > http://people.freedesktop.org/~pzanoni/0003-drm-i915-fixup-interlace-vertical-timings-confusion.patch.
> > Now my monitor reports "1080i" :)
> > 
> > Some notes about the patch:
> > 
> > - I really like your solution of not using CRTC_INTERLACE_HALVE_V,
> > because previously we were dividing by 2 and then multiplying by 2
> > again, which would not restore the original values in case of odd
> > numbers.
> > 
> > - I'm not sure about the change inside drm_modes.c. Why do we need the
> > "|= 1"? I fear it could cause us some troubles. This change might also
> > break the other drivers, of course. Wel'll need a "v4".
> > 
> > - It seems we need vtotal-- and vblank_end--. We need to find evidence
> > for that in the documentation. I'm just copying Windows
> > 
> > - I tested only on SNB. This time the screen looks good (previous
> > versions were really ugly). I'll test ilk and report if something goes
> > wrong...
> 
> I've updated my interlaced branch. Changes:
> - Adjust vertical timings as Paulo discovered. I've dropped the change in
>   drm_mode.c and instead substract one more from vtotal. I hope that this
>   results in the same configuration.
> - Added a paranoia patch to not set unsupported bits on gen2.
> - Addes support for vsyncshift. The hw seems to use that to correctly
>   insert the half-line delay when switching between even and odd fields.
>   That might also explain why we have to substract a little bit from
>   vtotal and vblank_end.
> 
> Testing feedback highly welcome. And if you can, please compare you
> register-settings with those from windows/bios. I'll also add the
> VSYNCSHIFT registers to intel_reg_dumper.

Paulo and me have crawled around in interlaced-land some more, and I think
we now have reasonable explanations plus patches for all the differences
between how windows sets things up on his machine and the current code.
I've updated my interlaced branch at:

http://cgit.freedesktop.org/~danvet/drm/log/?h=interlaced

Testing highly appreciated. Especially on analog TV-outputs - Rodrigo, can
you test this with your machines, please?

Cheers
-- 
Daniel Vetter
Mail: daniel at ffwll.ch
Mobile: +41 (0)79 365 57 48