On Thu, Jan 19, 2023 at 5:38 PM Hans de Goede <hdegoede@xxxxxxxxxx> wrote: > > 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(+) > > -- Both applied as 6.2-rc material, thanks!
