has the i915 "black screen" boot issue returned? [BISECTED]

[Chris Wilson]

On Fri, 28 Jan 2011 10:54:20 -0500 (EST), "Robert P. J. Day" <rpjday at crashcourse.ca> wrote:
> On Fri, 28 Jan 2011, Chris Wilson wrote:
> 
> > On Fri, 28 Jan 2011 10:27:09 -0500 (EST), "Robert P. J. Day" <rpjday at crashcourse.ca> wrote:
> > >   victory is mine!  ok, that premature return seems to have solved it,
> > > i'm up and running under this new kernel.  are we getting close?
> >
> > Not even close. We just disabled functionality that was working in 2.6.37;
> > the interaction between ACPI and gfx. What a shame.
> >
> > Instead of return -ENOTSUPP at the start,
> > you can return 0 before each of the if (mboxes & MBOX_*) to narrow down
> > which function regressed.
> 
>   ok, i'll see how much of that i can get to today.  but at this
> point, are we fairly convinced that there *is* a problem?  i'd hate to
> go through all this, only to learn at the end that it's something
> stupid i did.  it seems odd that no one else has mentioned running
> into this -- have you heard no other reports?

We're starting to get into ACPI backlight breakage territory...
We have identified that the regression was much earlier, just masked by
other breakage.

Let's clarify the symptoms: black panel, no backlight, no output at all
(not even at shallow angles), but the machine is alive? Can you remotely
access the machine and grab debug logs from when it is broken?
 
>   so, before i launch into this, is there anything else i might report
> about my system and its current setup that someone might want to know?

We're now just looking for telltale signs of an error.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre