I guess this commit solves the issue: 1b1ffc57a1b2 platform/x86: dell-laptop: Fix bogus keyboard backlight sysfs interface
Latest mainline kernel (v4.13-rc5) has this commit. Give it a try. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1478696 Title: dell-laptop: Incorrect keyboard backlight detection Status in linux package in Ubuntu: Triaged Bug description: I own Dell Inspiron M5110 (Q15R). This laptop has no keyboard backlight, but dell-laptop claims otherwise. My syslog was getting spammed with "Keyboard brightness level control not supported" as dell-laptop was trying to get/set backlight values. In dell-laptop there is kbd_led_present variable, but on my M5110 it's being set to true: ret = kbd_init_info(); (...) if (kbd_token_bits != 0 || ret == 0) kbd_led_present = true; kbd_token_bits is 0, but so is ret. kbd_init_info method is only returning != 0 if kbd_get_info is returning != 0 (Basing on this: http://linux.dell.com/cgi-bin/cgit.cgi/libsmbios.git/tree/src/bin/smbios-keyboard-ctl#n667) kbd_get_info method returns only cbRES1 value of following smbios call : cbClass 4 cbSelect 11 cbArg1 0x0 And it returns 0... I found that any cbRES of this call is giving me nothing but zeros, as if it wasn't defined in my BIOS. I have it's newest version for my laptop: [ 0.000000] SMBIOS 2.7 present. [ 0.000000] DMI: Dell Inc. Inspiron M5110/0X7W03, BIOS A05 03/22/2012 However, if "cbRES3, byte2 Number of keyboard light brightness levels" is 0 as well, that should mean backlight is not available, right? I'm attaching possible fix. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1478696/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp