On Sat, 18 Mar 2023 17:49:28 +0100, Hans de Goede wrote: > > Hi Takashi, > > On 3/17/23 11:04, Takashi Iwai wrote: > > Hi, > > > > we've received a regression report on openSUSE Bugzilla about the > > missing backlight control of nouveau device: > > https://bugzilla.opensuse.org/show_bug.cgi?id=1209296 > > > > On 6.1, with acpi_video=native option, the system provided > > /sys/class/backlight/nv_backlight entry. > > > > On 6.2, with acpi_video=native option, there is no entry in > > /sys/class/backlight. And without acpi_video option, it falls back to > > /sys/class/backlight/acpi_video0, which doesn't work as expected. > > > > Hans, could you check whether the recent change in video_detect.c (or > > anything else) may influence on this? My gut feeling is that the > > culprit could be rather some change in nouveau (so dri-devel is > > Cc'ed), but I'm not entirely sure... > > As I already told the reporter, who first contacted me by private email about this, all the drivers/acpi/video_detect.c changes which may influence this are also present in 6.1.y (IIRC >= 6.1.5) . So since this is being reported as only happening with 6.2.y I don't think the recent backlight detect rework is involved. > > And even if the recent backlight detect rework were involved, specifying acpi_backlight=native on the kernel commandline (as the reporter was doing before) should still work since it overrides all other backlight detection. > > So yes this seems to be a nouveau bug and should probably be reported following the instructions from: https://nouveau.freedesktop.org/Bugs.html (which I havealso told the reporter already). Thanks for verification! Takashi
