[Pm-utils] Resume Backlight Problems

[Dan Nicholson]

On Thu, Jul 2, 2009 at 10:44 PM, Lane Brooks<lane at brooks.nu> wrote:
> In July 2007 I had problems with the backlight on my Panasonic Toughbook
> resuming correctly after I moved from FC6 to FC7.  I upgraded to the
> kernel and pm-utils in the testing repo and submitted the patch with the
> appropriate quirks and suspend/resume were working fine.
>
> http://lists.freedesktop.org/archives/pm-utils/2007-July/000611.html
>
> I just made the jump from F8 to F11 on this laptop and resume is once
> again not turning the backlight on, even if I suspend with the vbe-post
> option manually.
>
> My initial guess is the problem is related to kernel mode setting.
> Kernel mode setting does not work correctly on my laptop, so I have to
> disable it with the nomodeset kernel option.  Is there some interaction
> pm-suspend and kernel mode setting that could be causing my problem?

Yes. If pm-utils sees that there is a drm fb, then it will skip
running any quirks itself. The idea is that if you're using kms, then
it will properly handle suspend and resume. Do you still have
/sys/class/drm/card0/device/graphics/fb0 when you boot with nomodeset?

You can probably get a better idea what's going on you can run
"PM_DEBUG=true pm-suspend" and look at /var/log/pm-suspend.log.

--
Dan