[Intel-gfx] [PATCH] drm/i915: disable_shared_pll doesn't work on pre-gen5

[Daniel Vetter]

On Mon, Aug 10, 2015 at 11:15:30AM +0100, Chris Wilson wrote:
> On Mon, Aug 03, 2015 at 01:09:11PM -0700, Jesse Barnes wrote:
> > Looks like
> > 
> > commit eddfcbcdc27fbecb33bff098967bbdd7ca75bfa6
> > Author: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> > Date:   Mon Jun 15 12:33:53 2015 +0200
> >     drm/i915: Update less state during modeset.
> > 
> > introduced the unconditional calling of disable_shared_dpll, but didn't
> > fix up pre-gen5 to avoid the BUG_ON at the top of the function.
> > 
> > So change the BUG_ON into a gen check (alternately we could move the
> > BUG_ON until later, since we shouldn't have a pll struct here either,
> > but this seems clearer to read).
> > 
> > This fixes a crash on load on my x200s platform.
> > 
> > Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
> 
> This blows up in 4.1 (a BUG_ON during boot causing a hard lockup).

The reference offending commit is 4.3 only. Are you sure it's the same
BUG_ON? Which machine?
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch