Hi Stepan, I'm mailing you because you are the author of: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=a11d342f I've been debugging the same problem together with a Fedora user: https://bugzilla.redhat.com/show_bug.cgi?id=1187004 And for him your fix does not work, before your fix landed we already came to the conclusion that to fix this we need to disable both the acpi_video backlight interface as well as the ideapad-laptop interface. Your patch only disables the acpi_video backlight interface (and as a side effect actually enables the ideapad-laptop interface). I assume that you've a working backlight setup on your Lenovo Ideapad Z570, can you please do: ls /sys/class/backlight And let us know which interfaces show up there. Either you do have a working ideapad_laptop interface, or you only get intel_backlight and for some reason ideapad_laptop is not loading on your system (not enabled in your kernel config, or blacklisted?). If you only have intel_backlight then that explains why things are not working for Be (the author of the Fedora bugreport), if you do have an ideapad_laptop interface and that does work for you, then it seems that not all Lenovo Ideapad Z570-s are created equal. In that case can you please blacklist the ideapad-laptop module, reboot and see if things still work for you when using intel_backlight to control the backlight? Once we've a confirmation that either you are already using intel_backlight, or that intel_backlight also works on your Ideapad, then I'll write a patch to replace yours which leaves only intel_backlight even if the ideapad-laptop driver gets loaded. Thanks & Regards, Hans -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
