Comment 169 for bug 207473

adding "acpi_backlight=vendor acpi_osi=linux" to grub boot options:
a. fully fixes this problem in a Dell Inspiron 1545 running 14.04 (all
behavior normal and as expected, including indicator popups for brightness
adjustment)
b. partially fixes the problem in a Dell Inspiron 1440 running 12.04 (full
access to all brightness levels via dedicated buttons, indicator pops up
but does not visually exhibit a brightness level change)

ethan

“A society grows great when its elders plant trees whose shade they know
they shall never sit in.” -- an ironic Greek proverb

On Sun, Aug 30, 2015 at 3:30 AM, Pavel Malyshev <email address hidden>
wrote:

> Just FYI:
> The bug, which Ubuntu cannot fix for 7 (SEVEN!!!) years, was fixed in
> Fedora in 1.5 months: https://bugzilla.redhat.com/show_bug.cgi?id=1141525
>
> ** Bug watch added: Red Hat Bugzilla #1141525
> https://bugzilla.redhat.com/show_bug.cgi?id=1141525
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/207473
>
> Title:
> Screen brightness double level changes on Dell laptops
>
> Status in Linux:
> Fix Released
> Status in hal package in Ubuntu:
> Invalid
> Status in kde-guidance package in Ubuntu:
> Fix Released
> Status in linux package in Ubuntu:
> Fix Released
> Status in hal source package in Hardy:
> Invalid
> Status in kde-guidance source package in Hardy:
> Fix Released
> Status in linux source package in Hardy:
> Invalid
>
> Bug description:
> Binary package hint: gnome-power-manager
>
> I have a fresh installation of Hardy with the latest updates installed
> on a Dell Inspiron 6400 laptop. The brightness settings (Fn+Up/Down)
> work although they seem to skip a level each time.
>
> '/proc/acpi/video/VID/LCD/brightness' tells me that it supports
> brightness levels 12, 24, 36, 48, 60, 72, 84 and 100. Without gnome-
> power-manager running pressing Fn+Up will transition up into each
> level and back down again smoothly.
>
> When gnome-power-manager is running increasing the brightness from 12
> I can only get levels 36, 60, 84 and 100. Decreasing the levels from
> 100 I only get 72, 48, 24 and 12. Running gnome-power-manager with the
> verbose option shows that when I press the brightness-up button once
> it is recorded twice. I ran gnome-power-manager in a debugger thinking
> it was a timing issue and it still happened.
>
> I have included the output from pressing the brightness-up button
> (Fn+Up) once below. This only happens when gnome-power-manager is
> running and did not happen using Feisty. I have looked at the code and
> I cannot see why the button event is triggered twice, I don't have any
> experience of the code but if you can give me any ideas of where to
> start I can try to look into this myself.
>
> Thanks!
>
>
> [hal_device_condition_cb] gpm-button.c:391 (00:11:48):
> condition=ButtonPressed, details=brightness-up
> [emit_button_pressed] gpm-button.c:335 (00:11:48): emitting
> button-pressed : brightness-up
> [button_pressed_cb] gpm-manager.c:999 (00:11:48): Button press
> event type=brightness-up
> [button_pressed_cb] gpm-srv-screensaver.c:167 (00:11:48): Button
> press event type=brightness-up
> [button_pressed_cb] gpm-backlight.c:563 (00:11:48): Button press
> event type=brightness-up
> [gpm_brightness_lcd_get_hw] gpm-brightness-lcd.c:116 (00:11:48):
> GetBrightness returned level: 0
> [gpm_brightness_lcd_set_hw] gpm-brightness-lcd.c:155 (00:11:48):
> Setting 1 of 7
> [gpm_brightness_lcd_up] gpm-brightness-lcd.c:362 (00:11:48): emitting
> brightness-changed (14)
> [brightness_changed_cb] gpm-backlight.c:755 (00:11:48): Need to
> display backlight feedback value 14
> [gpm_feedback_display_value] gpm-feedback-widget.c:144 (00:11:48):
> Displaying 0.140000 on feedback widget
> [gpm_refcount_add] gpm-refcount.c:100 (00:11:48): refcount now: 1
> [gpm_refcount_add] gpm-refcount.c:101 (00:11:48): non zero, so
> sending REFCOUNT_ADDED
> [brightness_changed_cb] gpm-backlight.c:759 (00:11:48): emitting
> brightness-changed : 14
> [button_pressed_cb] gpm-info.c:698 (00:11:48): Button press
> event type=brightness-up
> [hal_device_condition_cb] gpm-button.c:391 (00:11:48):
> condition=ButtonPressed, details=brightness-up
> [emit_button_pressed] gpm-button.c:335 (00:11:48): emitting
> button-pressed : brightness-up
> [button_pressed_cb] gpm-manager.c:999 (00:11:48): Button press
> event type=brightness-up
> [button_pressed_cb] gpm-srv-screensaver.c:167 (00:11:48): Button
> press event type=brightness-up
> [button_pressed_cb] gpm-backlight.c:563 (00:11:48): Button press
> event type=brightness-up
> [gpm_brightness_lcd_get_hw] gpm-brightness-lcd.c:116 (00:11:48):
> GetBrightness returned level: 1
> [gpm_brightness_lcd_set_hw] gpm-brightness-lcd.c:155 (00:11:48):
> Setting 2 of 7
> [gpm_brightness_lcd_up] gpm-brightness-lcd.c:362 (00:11:48): emitting
> brightness-changed (28)
> [brightness_changed_cb] gpm-backlight.c:755 (00:11:48): Need to
> display backlight feedback value 28
> [gpm_feedback_display_value] gpm-feedback-widget.c:144 (00:11:48):
> Displaying 0.280000 on feedback widget
> [gpm_refcount_add] gpm-refcount.c:100 (00:11:48): refcount now: 2
> [gpm_refcount_add] gpm-refcount.c:101 (00:11:48): non zero, so
> sending REFCOUNT_ADDED
> [brightness_changed_cb] gpm-backlight.c:759 (00:11:48): emitting
> brightness-changed : 28
> [button_pressed_cb] gpm-info.c:698 (00:11:48): Button press
> event type=brightness-up
> [gpm_refcount_auto_decrement] gpm-refcount.c:77 (00:11:50): refcount
> now: 1
> [gpm_refcount_auto_decrement] gpm-refcount.c:74 (00:11:50): zero, so
> sending REFCOUNT_ZERO
> [gpm_feedback_close_window] gpm-feedback-widget.c:134 (00:11:50):
> Closing feedback widget
>
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