[Intel-gfx] [PATCH 2/4] drm/i915: Leave LVDS registers unlocked
jbarnes at virtuousgeek.org
Mon Aug 8 13:25:31 PDT 2011
On Mon, 08 Aug 2011 13:24:12 -0700
Keith Packard <keithp at keithp.com> wrote:
> On Mon, 8 Aug 2011 13:01:28 -0700, Jesse Barnes <jbarnes at virtuousgeek.org> wrote:
> > 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.
> I'll leave the optimization in place then; it's been there for a while
> so at least it shouldn't cause any regressions.
> How about this? Has the advantage of not lying in the commit message
> From 092719152aa5a235d6678798a34dc784d5cec2ad Mon Sep 17 00:00:00 2001
> From: Keith Packard <keithp at keithp.com>
> Date: Sat, 6 Aug 2011 10:33:12 -0700
> Subject: [PATCH 2/5] drm/i915: Leave LVDS registers unlocked
> There's no reason to relock them; it just makes operations more
> complex. This fixes DPMS where the panel registers were locked making
> the disable not work.
> Signed-off-by: Keith Packard <keithp at keithp.com>
Yeah looks like a nice improvement.
Reviewed-by: Jesse Barnes <jbarnes at virtuousgeek.org>
Jesse Barnes, Intel Open Source Technology Center
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