resume fails to light display on Macbook Pro Retina on 3.8-rc1

[James Courtier-Dutton]

On 28 February 2013 00:02, Greg KH <gregkh at linuxfoundation.org> wrote:
> On Wed, Feb 27, 2013 at 11:27:30PM +0000, James Courtier-Dutton wrote:
>> On 26 February 2013 18:11, James Courtier-Dutton <james.dutton at gmail.com> wrote:
>> > On 26 February 2013 17:35, Greg KH <gregkh at linuxfoundation.org> wrote:
>> >> On Mon, Feb 25, 2013 at 07:45:45PM -0800, Greg KH wrote:
>> >>> On Mon, Feb 25, 2013 at 02:32:43PM -0800, Greg KH wrote:
>> >>> > On Mon, Feb 25, 2013 at 04:06:02PM +1000, Dave Airlie wrote:
>> >>> > > On Mon, Feb 25, 2013 at 3:52 PM, Greg KH <gregkh at linuxfoundation.org> wrote:
>> >>> > > > Hi Ben,
>> >>> > > >
>> >>> > > > My Macbook Pro Retina fails to resume properly on 3.8.  I tracked this
>> >>> > > > down to commit 6c5a04249d7afeea3e0ed971e7813f84e29a1706 (drm/nvd0/disp:
>> >>> > > > move link training helpers into core as display methods)
>> >>> > > >
>> >>> > > > Anything I can try to help solve this?
>> >>> > > >
>> >>> > > > Note, I'm using the Intel driver as the main controller for this laptop,
>> >>> > > > well, I think I am, my xorg log is attached.
>> >>> > >
>> >>> > > No you are using the nvidia, the efi always boots nvidia enabled now.
>> >>> >
>> >>> > Really?  When did that change?  I thought I wanted to be using the Intel
>> >>> > chip to save battery life.
>> >>> >
>> >>> > > btw I just tested my drm-next tree on mine and it resumed the display
>> >>> > > fine, something oopsed a few seconds later that I haven't tracked down
>> >>> > >
>> >>> > > git://git.freedesktop.org/~airlied/linux drm-next
>> >>> > >
>> >>> > > I'll be sending it to Linus this evening or tomorrow morning, once I
>> >>> > > fix my tree.
>> >>> >
>> >>> > Ok, I'll test again when it hits Linus's tree, and if that works, it
>> >>> > would be good to try to work out what patch fixes it to get them into
>> >>> > the 3.8-stable series so that others don't run into the same problem.
>> >>>
>> >>> I've tested Linus's tree now (I'm guessing it has all of your changes in
>> >>> it), and it works!
>> >>>
>> >>> I see a bunch of patches marked for the stable branch, so I'll try those
>> >>> out and see if they fix the problem.  If not, I'll let you and Ben know.
>> >>
>> >> I've applied the radeon patches tagged for -stable and tested that on
>> >> 3.8.0, but that doesn't solve the resume problem.  Any ideas of anything
>> >> else I can do to test this?  Doing a "backwards" git-bisect is a pain,
>> >> but I guess I can do that to try to track down what patch fixed this, if
>> >> that's the only idea people have...
>> >>
>> >
>> > If it helps, I have a similar resume problem here.
>> > 3.7.8 good
>> > 3.8.0 bad
>> >
>> > Laptop with no nvidia, no amd graphics, just Intel Graphics 4000, 3rd
>> > Gen I5 CPU.
>>
>> Problem: "Backlight not coming on after resume."
>> git finally bisected  for my Samsung Serial 7 Laptop.
>> Bisecting: 0 revisions left to test after this (roughly 0 steps)
>> [cf0a6584aa6d382f802f2c3cacac23ccbccde0cd] drm/i915: write backlight
>> harder     <- This is the problem commit. Seems that fixing some
>> machines breaks others, based on the existing comments on that patch.
>
> Hm, so, 3.8.0 works for you, but 3.8.1-rc1 doesn't?  Or are you saying
> Linus's tree doesn't work for you?
>
> As you have a different issue here than the nvidia hardware I was
> dealing with, you might want to try to start over with a new thread and
> the needed info, and the needed people on it (i.e. the i915
> maintainers and mailing list.)
>
I little confusing sorry.
I started using:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
For that 3.7.8 worked fine, 3.8 failed to restore X, but the backlight lights.

I then moved to linus tree at:
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
On Linus tree the problem commit is:
[cf0a6584aa6d382f802f2c3cacac23ccbccde0cd] drm/i915: write backlight harder
The problem on the Linux tree is different from the stable tree.
Linus tree: Backlight fails to light up after resume.
linux-stable tree: Failed to restore X, but the backlight lights.

So, I think the linus tree fixes the "failed to restore X" bit, but
introduced a new regression for the backlight.
I don't know which patch from the Linus tree would fix the stable 3.8 tree.

I will send an email to the i915 maintainers tomorrow.