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

[Robert P. J. Day]

On Fri, 28 Jan 2011, Chris Wilson wrote:

> On Fri, 28 Jan 2011 04:24:17 -0500 (EST), "Robert P. J. Day" <rpjday at crashcourse.ca> wrote:
> > On Fri, 28 Jan 2011, Chris Wilson wrote:
> >
> > > Well, we have two endpoints, so let git attack:
> > >
> > > $ git bisect start
> > > $ git bisect good 58bbf018a70c562437eeae121a5d021ba7fe56a5
> > > $ git bisect bad abb72c828878a2c69b2cfb33ac30007c8ecd735e
> > >
> > > That shouldn't take more than a few recompiles to identify the
> > > troublemaker.
> >
> >   ok, i can get to that in a bit.  might take a while since this
> > system is not exactly a screamer but i'm curious -- have you heard no
> > other reports of people running into this issue?  i'm going to be
> > embarrassed if it turns out it's something *i've* done but, at this
> > point, it seems fairly reproducible.
>
> This is the first I'm aware of. It could just be the tip of the iceberg...

  the git bisection finally resolved to:

  BAD:  b705120e
  GOOD: 8a327f23

so the culprit appears to be:

b705120e4198315f4ae043de06c62f65e0851fd3 is the first bad commit
commit b705120e4198315f4ae043de06c62f65e0851fd3
Author: Michael Karcher <kernel at mkarcher.dialup.fu-berlin.de>
Date:   Sun Jan 23 18:17:17 2011 +0000

    drm/i915: Use consistent mappings for OpRegion between ACPI and i915

    The opregion is a shared memory region between ACPI and the graphics
    driver. As the ACPI mapping has been changed to cachable in commit
    6d5bbf00d251cc73223a71422d69e069dc2e0b8d, mapping the intel opregion
    non-cachable now fails. As no bus-master hardware is involved in the
    opregion, cachable map should do no harm.

    Tested on a Fujitsu Lifebook P8010.

    Signed-off-by: Michael Karcher <kernel at mkarcher.dialup.fu-berlin.de>
    [ickle: convert to acpi_os_ioremap for consistency]
    Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>


  thoughts?  once again, the salient output from "lspci -v":

00:02.0 VGA compatible controller: Intel Corporation Core Processor
Integrated Graphics Controller (rev 12) (prog-if 00 [VGA controller])
        Subsystem: Acer Incorporated [ALI] Device 031c
        Flags: bus master, fast devsel, latency 0, IRQ 41
        Memory at d0000000 (64-bit, non-prefetchable) [size=4M]
        Memory at c0000000 (64-bit, prefetchable) [size=256M]
        I/O ports at 3050 [size=8]
        Expansion ROM at <unassigned> [disabled]
        Capabilities: <access denied>
        Kernel driver in use: i915
        Kernel modules: i915


rday

-- 

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Robert P. J. Day                               Waterloo, Ontario, CANADA
                        http://crashcourse.ca

Twitter:                                       http://twitter.com/rpjday
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