Re: [3/3] 2.6.21-rc7: known regressions (v2)

Antonino A. Daplas
2007-04-25T13:52:16Z

Forgot to add Richard, sorry for the double post.

On Wed, 2007-04-25 at 21:50 +0800, Antonino A. Daplas wrote:
> On Wed, 2007-04-25 at 09:01 -0400, Dave Jones wrote:
> > On Wed, Apr 25, 2007 at 01:31:02PM +0200, Adrian Bunk wrote:
> > > On Wed, Apr 25, 2007 at 04:06:05AM -0700, Andrew Morton wrote:
> > > > On Mon, 23 Apr 2007 23:49:09 +0200 Adrian Bunk <bunk@stusta.de> wrote:
> > > >...
> > > > > Subject : ThinkPad X60: resume no longer works (PCI related?)
> > > > > workaround: CONFIG_FB_BACKLIGHT=n
> > > > > References : http://lkml.org/lkml/2007/3/13/3
> > > > > Submitter : Dave Jones <davej@redhat.com>
> > > > > Caused-By : PCI merge
> > > > > commit 78149df6d565c36675463352d0bfe0000b02b7a7
> > > > > Handled-By : Eric W. Biederman <ebiederm@xmission.com>
> > > > > Rafael J. Wysocki <rjw@sisk.pl>
> > > > > Antonino A. Daplas <adaplas@gmail.com>
> > > > > Status : unknown
> > > >
> > > > Is this related to the problems Jeremy has been looking at?
> > > >...
> > >
> > > Dave and Jeremy hran into similar looking but most likely different
> > > problems.
> > >
> > > For Jeremy -rc7 is working fine, but for Dave it doesn't.
> >
> > I think this was due to Jeremy not having CONFIG_FB_BACKLIGHT=y in his config.
>
> This is really weird, as CONFIG_FB_BACKLIGHT just selects
> BACKLIGHT_CLASS and LCD_CLASS, and adds an entry (bl_curve)
> under /sys/class/backlight/*/. ACPI_IBM which is set (presumably) in
> Dave's kconfig, also selects the BACKLIGHT_CLASS. And the only possible
> framebuffer drivers in the thinkpad are vesafb and intelfb, none of
> which has a backlight driver.
>
> I'm still at a loss how this happens. Dave, can you post your config?
> And have you tried the following settings:
>
> FB_BACKLIGHT=y
> ACPI_IBM=n
> ACPI_VIDEO=n
>
> I'm also adding Richard Purdie to the CC list.
>
> Tony
>
> PS: I also get a blank display on resume with a Toshiba laptop. But
> cycling through the Fn keys brings it back. I don't know if this is a
> regression, I will have to try older kernels.
>