My minnow was broken by: drm/i915: Consolidate forcewake code

[Darren Hart]

+Jani

Jani, I think this may have inadvertently undone the fix you made for
us on the MinnowMax.

On Fri, Jan 23, 2015 at 1:44 PM, Olof Johansson <olof at lixom.net> wrote:
> Hi Daniel, Mika,
>
> For the first time in a few days, -next was bootable last night. I
> noticed that my Minnowboard Max didn't actually boot though, it got
> stuck shortly after or during DRM probing:
>
> http://arm-soc.lixom.net/bootlogs/next/next-20150123/minnowmax-x86-minnowmax_defconfig.html
>
> I bisected it down to the below patch that I failed to find posted
> (with that subject) anywhere on a public list that I am subscribed to.
>
> The patch isn't revertable without considerable effort so I can't
> double check that it's just this one change, but the commit before
> that in the branch boots, this one does not.
>
>
> commit fc72355f5c04c40f2916a07e9f8d4b357e2e0a93
> Author:     Mika Kuoppala <mika.kuoppala at linux.intel.com>
> AuthorDate: Mon Jan 19 16:20:43 2015 +0200
> Commit:     Daniel Vetter <daniel.vetter at ffwll.ch>
> CommitDate: Tue Jan 20 12:36:57 2015 +0100
>
>     drm/i915: Consolidate forcewake code
>
>     As we now have forcewake domains, take advantage of it
>     by putting the differences in gen fw handling in data rather
>     than in code.
>
>     In past we have opencoded this quite extensively as the fw handling
>     is in the fast path. There has also been a lot of cargo-culted
>     copy'n'pasting from older gens to newer ones.
>
>     Now when the releasing of the forcewake is done by deferred timer,
>     it gives chance to consolidate more. Due to the frequency of actual hw
>     access being significantly less.
>
>     Take advantage of this and generalize the fw handling code
>     as much as possible. But we still aim to keep the forcewake sequence
>     particularities for each gen intact. So the access pattern
>     to fw engines should remain the same.
>
>     v2: - s/old_ack/clear_ack (Chris)
>         - s/post_read/posting_read (Chris)
>         - less polite commit msg (Chris)
>
>     v3: - rebase
>         - check and clear wake_count in init
>
>     v4: - fix posting reads for gen8 (PRTS)
>
>     Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>
>     Reviewed-by: Deepak S <deepak.s at linux.intel.com> (v2)
>     Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>



-- 
Darren Hart