[Intel-gfx] [PATCH 2/4] drm/i915: Leave LVDS registers unlocked

[Jesse Barnes]

On Mon, 08 Aug 2011 12:53:31 -0700
Keith Packard <keithp at keithp.com> wrote:

> On Mon, 8 Aug 2011 11:49:54 -0700, Jesse Barnes <jbarnes at virtuousgeek.org> wrote:
> 
> > Yep, it's safe and possible to do on pre-PCH as well.  For panel
> > fitting we do need to do an actual power cycle when going from
> > non-native back to native iirc, but we can still leave them unlocked so
> > we don't have to worry about the lock/unlock sequence everywhere.
> 
> Hidden in the unlock patch was a call to intel_lvds_disable from
> intel_lvds_prepare -- that *always* turns off the LVDS for mode
> setting. Do we care enough about LVDS mode setting performance that we
> should try leave the optimization in place that doesn't turn off the
> backlight when switching between modes?

We hate flicker right?  But generally yes it's safer to just turn it
off all the time.

-- 
Jesse Barnes, Intel Open Source Technology Center