The culprit here is gnome-power-manager. Although the backlight of my laptop display is at full brightness when g-p-m starts, it uses a cached value (brightness 0, which is wrong) and then dims it up from there to full brightness. I connected my laptop to AC before starting up.
I captured the verbose output of g-p-m when it is started by GDM. The relevant lines should be: TI:20:22:31 TH:0xcfe890 FI:gpm-backlight.c FN:gpm_backlight_brightness_evaluate_and_set,216 - 1. main brightness 1,000000 TI:20:22:31 TH:0xcfe890 FI:gpm-backlight.c FN:gpm_backlight_brightness_evaluate_and_set,236 - 2. battery scale 1,000000, brightness 1,000000 TI:20:22:31 TH:0xcfe890 FI:gpm-backlight.c FN:gpm_backlight_brightness_evaluate_and_set,254 - 3. idle scale 1,000000, brightness 1,000000 *** WARNING *** TI:20:22:31 TH:0xcfe890 FI:gpm-brightness.c FN:gpm_brightness_trust_cache,107 - using cache for value 0 (probably okay) TI:20:22:31 TH:0xcfe890 FI:gpm-brightness-hal.c FN:gpm_brightness_hal_dim_hw,243 - new_level_hw=15 TI:20:22:31 TH:0xcfe890 FI:gpm-brightness-hal.c FN:gpm_brightness_hal_dim_hw_step,200 - new_level_hw=15, last_set_hw=0 TI:20:22:31 TH:0xcfe890 FI:gpm-brightness-hal.c FN:gpm_brightness_hal_set_hw,155 - Setting 0 of 15 TI:20:22:31 TH:0xcfe890 FI:gpm-brightness-hal.c FN:gpm_brightness_hal_set_hw,155 - Setting 1 of 15 [...] TI:20:22:32 TH:0xcfe890 FI:gpm-brightness-hal.c FN:gpm_brightness_hal_set_hw,155 - Setting 15 of 15 TI:20:22:32 TH:0xcfe890 FI:gpm-backlight.c FN:gpm_backlight_brightness_evaluate_and_set,287 - emitting brightness-changed : 100 Full log is attached. ** Attachment added: "gpm_gdmlog.txt" http://launchpadlibrarian.net/32270528/gpm_gdmlog.txt -- xsplash dims and undims despite power settings disabling dimming the screen https://bugs.launchpad.net/bugs/434353 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
