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

From: Jesse Barnes
Date: Mon Aug 08 2011 - 14:50:15 EST

On Mon, 08 Aug 2011 11:42:56 -0700
Keith Packard <keithp@xxxxxxxxxx> wrote:

> On Mon, 8 Aug 2011 09:30:10 -0700, Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx> wrote:
> > Yep, looks fine. The only think we might want to sprinkle about are
> > checks for panel off so we can avoid visible corruption if we whack
> > timing or fb stuff while the panel is on.
> So, I'd like to know if we could unlock the panel registers on pre-PCH
> hardware as well at init time; that way I could remove the unlock code
> From intel_lvds_prepare too. Should it be possible to set the
> PANEL_UNLOCK_REGS bits for pre-PCH hardware without having the target off?

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.

Jesse Barnes, Intel Open Source Technology Center
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