The Fedora fix seems much more elegant and less invasive by simply finding
and eliminating a software keymapping duplicate of hardware/bios activated
keys, if it's the same issue!  Maybe it's part of the fix, because the
Inspiron 1545 running 14.04 already has those changes in its
/lib/udev/hwdb.d/60-keyboard.hwdb

# Dell Inspiron 1520
keyboard:dmi:bvn*:bvr*:bd*:svnDell*:pnInspiron*1520:pvr*
 KEYBOARD_KEY_85=unknown  # Brightness Down, also emitted by acpi-video,
ignore
 KEYBOARD_KEY_86=unknown  # Brightness Up, also emitted by acpi-video,
ignore

although perhaps we need to generalize this to more Dells and activate it
via the computer model identifier referenced in the Fedora bug?

ethan

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


On Mon, Aug 31, 2015 at 2:07 PM, ethan a young <email address hidden> wrote:

> 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
>>
>> To manage notifications about this bug go to:
>> https://bugs.launchpad.net/linux/+bug/207473/+subscriptions
>>
>
>