Bug 82921

Summary:	Keyboard backlight configured to use Fn+Z randomly turns itself on
Product:	Drivers	Reporter:	Marcelo Ruiz (marcelo_javier_ruiz)
Component:	Platform_x86	Assignee:	drivers_platform_x86 (drivers_platform_x86)
Status:	ASSIGNED ---
Severity:	low	CC:	alan, coproscefalo, rui.zhang
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	3.16.1	Subsystem:
Regression:	No	Bisected commit-id:

Description Marcelo Ruiz 2014-08-20 23:37:33 UTC

From bug https://bugzilla.kernel.org/show_bug.cgi?id=32742 I learned that the from Kernel 3.15 the Fn+Z function should be working on my Toshiba Qosmio X500, so I installed 3.16.1 and it does work: I can turn the keyboard backlight on and off. The only problem is that if it is off, eventually it will turn itself on by itself after a short period of time.

Comment 1 Zhang Rui 2014-08-21 15:16:32 UTC

This does not seems to be an ACPI problem.
does the keyboard backlight work if you blacklist toshiba-acpi driver?

Comment 2 Zhang Rui 2014-09-09 14:48:57 UTC

ping...

Comment 3 Marcelo Ruiz 2014-09-12 03:55:50 UTC

I created a file called /etc/modprobe.d/blacklist-toshiba-acpi with the content:
'blacklist toshiba_acpi' (with no quotes and underscore).
After reboot, the output of 'lsmod | grep 'toshiba" gives me:

toshiba_bluetooth      12867  0 
toshiba_acpi           28375  0 
sparse_keymap          13890  1 toshiba_acpi
wmi                    19379  1 toshiba_acpi

The backlight keyboard does work after doing that.

Comment 4 Azael Avalos 2014-09-24 17:25:36 UTC

(In reply to Zhang Rui from comment #1)
> This does not seems to be an ACPI problem.
> does the keyboard backlight work if you blacklist toshiba-acpi driver?

Right, the driver only exposes a LED device, but the kernel does not control such LED (unless a distro specific patch is applied and controls it, which I really doubt it), it's up to userspace apps, daemons, etc., to turn it on/off.

(In reply to Marcelo Ruiz from comment #3)
> I created a file called /etc/modprobe.d/blacklist-toshiba-acpi with the
> content:
> 'blacklist toshiba_acpi' (with no quotes and underscore).
> After reboot, the output of 'lsmod | grep 'toshiba" gives me:
> 
> toshiba_bluetooth      12867  0 
> toshiba_acpi           28375  0 
> sparse_keymap          13890  1 toshiba_acpi
> wmi                    19379  1 toshiba_acpi
> 
> The backlight keyboard does work after doing that.

AFAIK, all the files under modprobe.d MUST have the .conf extension in order to get loaded, that's why toshiba_acpi is not blacklisted at all.

Comment 5 Zhang Rui 2014-09-25 02:00:45 UTC

re-assign to the toshiba_acpi driver experts.

Comment 6 Marcelo Ruiz 2014-09-26 01:53:34 UTC

Sorry, my bad. I renamed the file to end in .conf
Now the output of lsmod | grep 'toshiba' returns only:

toshiba_bluetooth      12867  0 

The keyboard backlight still works when I press Fn+Z.
Anything else that need to be tested?

Comment 7 Azael Avalos 2014-09-26 02:33:25 UTC

(In reply to Marcelo Ruiz from comment #6)
> Sorry, my bad. I renamed the file to end in .conf
> Now the output of lsmod | grep 'toshiba' returns only:
> 
> toshiba_bluetooth      12867  0 
> 
> The keyboard backlight still works when I press Fn+Z.

Well, that's new, your model and mine (X505) share the same motherboard and BIOS, and I was really expecting the keyboard backlight not to work anymore, which seems an indications that is being controlled internally via embedded firmware.

> Anything else that need to be tested?

Just make sure you are on the latest BIOS, IIRC, it shoud be 1.90

Comment 8 Marcelo Ruiz 2014-09-26 16:02:43 UTC

My BIOS version is 1.90