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

From: Jesse Barnes
Date: Mon Aug 08 2011 - 16:01:47 EST

On Mon, 08 Aug 2011 12:53:31 -0700
Keith Packard <keithp@xxxxxxxxxx> wrote:

> On Mon, 8 Aug 2011 11:49:54 -0700, Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx> 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
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