Using the -r1-noblpatch kernel (the clean one), I get a shortened
"range" i.e. I can use ~30%-70% but accessing values outside that range
causes flickering (using gnome3 and the Fn+F7/F8 keys). This seems to be
dependent on the value of /sys/class/backlight/acpi_video0/brightness

I manually incremented /sys/class/backlight/acpi_video0/brightness in
sets of ten (initially one by one) and no new messages appeared in
dmesg, apart from one more of the thinkpad_acpi ones that is also at the
base of the previous upload. The brightness changed fine using this
method.

"cat /sys/class/backlight/acpi_video0/max_brightness" returns 100.

Using previous kernels (anything >=3.7) I would get exactly the
behaviour described in the bug report (unable to shift below ~90%).

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1098216

Title:
  Regression in brightness control on Lenovo Thinkpad X230 and X1 Carbon

To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/1098216/+subscriptions

-- 
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to