Re: [Regression] Laptop screen dark when lid closed and reopened.with 3.1

[Alex Davis <alex14641@yahoo.com>]

From: Keith Packard <keithp@keithp.com>

To: Alex Davis <alex14641@yahoo.com>; "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Cc: 
Sent: Saturday, September 24, 2011 10:48 AM
Subject: Re: [Regression] Laptop screen dark when lid closed and reopened.with 3.1

>If you can, please send along a kernel log with drm.debug=5 and the
>output of intel_reg_dumper run when the screen is working and when it is
>black -- you'll need to use ssh from another computer to capture the
>latter.
>
>intel_reg_dumper can be found at:
>
>        git://anongit.freedesktop.org/git/xorg/app/intel-gpu-tools
>
>I suspect you're hitting some of the backlight changes. Hard to believe
>that something as simple as a light could be so complicated...

Thanks for the info, will do this early next week.

One good thing about the 3.1 kernels is that I now have the /sys/class/backlight/intel_backlight directory
in addition to /sys/class/backlight/dell_backlight. With intel_backlight, I can control the LCD brightness;
dell_backlight never worked, neither in 3.0 or 3.1.