@Joshua-

> * How can I manually induce a display suspend?

$ sudo /usr/sbin/pm-suspend

> * How do I manually change the display brightness level?

You should be able to run this sequence from a terminal window on your
external monitor (or while logged in to the laptop from another machine)
-- it will reflect and affect the laptop display brightness.   When the
laptop screen is stuck in its dark state after resume, does the
'brightness' value below display as zero?  Does that value seem to
change when you press the brightness up/down keys?:

$ cd /sys/class/backlight/intel_backlight
$ cat max_brightness
{note the max brightness value (it won't ever change)}
$ cat brightness
{note the current brightness value; it *should* reflect the laptop screen 
backlight brightness, from 0 (off) to the max value}

You can change the brightness value manually as follows.  Does changing
it actually affect the screen brightness (once you're in the stuck dark
state) or not?

$ cd /sys/class/backlight/intel_backlight
$ echo {somevalue} | sudo tee brightness
Replace "{somevalue}" with the max brightness value.

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/872652

Title:
  Display Hang With acpi_backlight=vendor

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/872652/+subscriptions

-- 
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to