[Intel-gfx] Critical regression in 4.7-rcX

[Larry Finger]

On 07/15/2016 09:43 AM, Ville Syrjälä wrote:
> On Fri, Jul 15, 2016 at 04:27:27PM +0200, Daniel Vetter wrote:
>> On Fri, Jul 15, 2016 at 8:55 AM, Linus Torvalds
>> <torvalds at linux-foundation.org> wrote:
>>> On Thu, 14 Jul 2016, Larry Finger wrote:
>>>> To anyone keeping track of regressions in kernel 4.7, I call your attention to
>>>> https://bugs.freedesktop.org/show_bug.cgi?id=96675.
>>>>
>>>> This bug causes driver i915 to fail to connect to the display, and results in
>>>> a blank screen as soon as the kernel is loaded. The only way to operate with
>>>> kernel 4.7 is to add "nomodeset" to the command line. The problem was bisected
>>>> to commit f21a21983ef13a ("drm/i915: Splitting intel_dp_detect").
>>>
>>> Daniel? Jani? Time to revert?
>>
>> Yup. Means that I'll get to revert a pile of patches (plus even more
>> in -next), but that's what we get for not handling regressions timely.
>> Dave poked me about the same bug already too. But will take a few days
>> until the pull is in your inbox I guess.
>
> I attached a oneliner to the bug today, that I *think* should fix the
> problem.

After I checked out the problem commit and built that kernel with the one-line 
patch, the display works; however, mainline still fails. I am currently 
bisecting to find what other commit fails. At a minimum, we should be able to 
reduce the number of commits that need reverting.

Larry