24 Feb
2014
24 Feb
'14
12:11 p.m.
On Mon, Feb 24, 2014 at 12:48:55PM +0900, Michel Dänzer wrote:
On Fre, 2014-02-21 at 21:03 +0200, ville.syrjala@linux.intel.com wrote:
We can kill of the drm_vblank_{pre,post}_modeset() calls since those are there simply to make drm_vblank_get() fail during a modeset.
Actually, their original purpose was to keep the DRM vblank counter consistent across modesets, assuming the modeset resets the hardware vblank counter.
I see. Well, actually I really don't. The code is too funky for me to tell what it actually ends up doing. The obvious way would be to resample the hardware counter at drm_vblank_post_modeset(), which the code certainly doesn't do. But maybe it did something sensible in the past.
--
Ville Syrjälä
Intel OTC