[Intel-gfx] [PATCH 1/4] drm/i915: rip out intel_disable_pch_ports

[Jesse Barnes]

On Thu,  6 Sep 2012 22:08:32 +0200
Daniel Vetter <daniel.vetter at ffwll.ch> wrote:

> Even with the old crtc helper code we should have disabled all
> encoders on that pipe by now, and with the new code this would
> definitely paper over a bug. We already have the necessary checks
> in place in intel_disable_transcoder, so if we accidentally leave
> a pch port on, this will be caught.
> 
> Hence just rip this all out.
> 
> Note that up to the patch in this giant modeset series that removes
> the LVDS special case to avoid disabling LVDS in the encoder->prepare
> callback ("drm/i915/lvds: ditch ->prepare special case"), this was not
> the case for all outputs.
> 
> Also note that in
> 
> commit 1b3c7a47f993bf9ab6c4c7cc3bbf5588052b58f4
> Author: Zhenyu Wang <zhenyuw at linux.intel.com>
> Date:   Wed Nov 25 13:09:38 2009 +0800
> 
>     drm/i915: Fix LVDS stability issue on Ironlake
> 
> this was already discovered independently and worked around. How I
> bloody hate this entire mess of cludges piled on top of other cludges.

Yes this was always an ugly layering violation too.  I think I was
worried about a mode set on one crtc getting stale config bits from
another that hadn't been touched...

Anyway now we've fixed it properly.

Reviewed-by: Jesse Barnes <jbarnes at virtuousgeek.org>

-- 
Jesse Barnes, Intel Open Source Technology Center