I was not able to open an upstream bug at bugzilla.kernel.org because it is still offline.
It turns out that this laptop requires the 'samsung-laptop' platform driver in order for backlight control to work. The driver contains a whitelist of the DMI strings of models known to require this driver. This laptop identifies itself thusly: $ sudo dmidecode -s system-product-name N150P The attached patch adds this model to the whitelist which causes the driver to load and work as expected. The boot parameter "acpi_backlight=vendor" seems to have the same ultimate affect as this patch but needs to be manually set. I have forwarded the patch upstream: https://lkml.org/lkml/2011/12/22/364 and http://thread.gmane.org/gmane.linux.drivers.platform.x86.devel/2808 ** Patch added: "lp875893.patch" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/875893/+attachment/2644767/+files/lp875893.patch -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/875893 Title: Samsung N150 Plus backlight does not work with ACPI driver To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/875893/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
