Hi Rafael, With the backlight changes landing in 6.1.y now showing up in distribution repositories I have been receiving a steady stream of backlight bug reports by email. These bug-reports fall into various categories and most of them are already fixed with some recent fixes which are in 6.1.7 and later. One category (unfortunately) requires adding DMI quirks. I have been receiving reports from users with pre Windows 8 laptops, who used to pass acpi_backlight=vendor on the kernel commandline to hide a non functioning acpi_video# backlight device, so that userspace will use the native (GPU driver) backlight device instead. Starting with 6.1.y acpi_backlight=vendor is now also honored by the native backlight drivers, hiding the native backlight device, leaving these users with no backlight device at all. This leads to them sending me a bug-report. Which in a way is a good thing because these models really needed to have a DMI quirk added all along, but this was never reported upstream. The fix here is to use "acpi_backlight=native" and to set this through a DMI quirk so that things will work out of the box. The Acer Aspire 4810T quirk from a couple of days was like this and the first quirk in this series is too. I expect to receive more bug-reports like this, so you can expect a steady trickle of backlight quirk patches from me the coming time. Note the second quirk in this series is also a "acpi_backlight=native" quirk, but the root cause is somewhat different, see the commit msg. Regards, Hans Hans de Goede (2): ACPI: video: Add backlight=native DMI quirk for HP Pavilion g6-1d80nr ACPI: video: Add backlight=native DMI quirk for HP EliteBook 8460p drivers/acpi/video_detect.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) -- 2.39.0
