Revision of hald-addon-dell-backlight needed

[Linard Verstraete]

Binary package hint: hal

Personally I think it's needed to revise hald-addon-dell-backlight.

I have a Dell Vostro 1500, that shipped with Vista. I'm now running it in dual boot with "Xubuntu 8.04".
Now, on my (X)ubuntu I'm able to change the brightness of my LCD-pannel with the FN-keys. In my process-list I see this process:"hald-addon-dell-backlight". But I think it does nothing... Because when I kill "hald-addon-dell-backlight", I can still change the brightness of my LCD-pannel.

[Linard Verstraete (linardv)]

Changed status to confirmed since:
Hinrik Örn Sigurðsson reported the same problem in bug #277954.

[Andrea Ratto (andrearatto)]

FN keys work at a hardware level, so they always work.
hald-addon-dell-backlight does this:
listen for changes by the FN-keys and notifies software that cares about it (through HAL)
lets the brightness be changed by software (through HAL as well), eg, after some inactivity

I think this bug can be closed...

[Linard Verstraete (linardv)]

Do I understand this correctly, if I say there are more then 1 listeners for the FN-keys?
One listener is hald-addon-dell-backlight and if you kill it, hitting FN-keys will still work because another listener will capture the event. That would explain why killing hald-addon-dell-backlight keeps it working.

A second thing why I thought revision was needed, is the fact that hitting the FN-keys once makes the brightness changes several levels. There are numerous bug reports about this like bug #207473, in my personal case it changes with steps of 4 levels. A small test reveals that if I kill hald-addon-dell-backlight process it still changes by 4 levels. So hald-addon-dell-backlight can't have anything to do with this, right?

But this makes me question: if hitting FN-keys are properly handled without hald-addon-dell-backlight, why does it still exists? (Without it would save us resources and it would be a process less that needed to be started upon boot-time.)

[Linard Verstraete (linardv)]

Oh, and another question: there have been reports of hald-addon-backlight consumes up to 100% of CPU. (Reference: bug #285323, comments 56 & 57). Shouldn't that be a reason too to revise the hald-addon-backlight.

[Linard Verstraete (linardv)]

Oh, and another question: there have been reports of hald-addon-backlight consumes up to 100% of CPU. (Reference: bug #285323, comments 56 & 57). Shouldn't that be a reason too to revise the hald-addon-backlight?

[Linard Verstraete (linardv)]

Sorry for the double post :S ...

[Andrea Ratto (andrearatto)]

without hald-addon-dell-backlight you can change brightness only through FN-keys, which work at a hardware level, (at least on many models).
thanks to hald-addon-dell-backlight, you can change brightness trough software, and get a nice screen notification when you use the FN-keys.
If you don't like it, probably there is a tricky way to deactivate it.

There are good reason for revising every software in existence, but bugs like this do not have any effect at all. Following and investigating bugs for the individual problems is the way to go. Abusing bug traking for else, just wastes developers and other people's time.
And I think they know how in bad shape libsmbios and hald-addon-dell-backlight are. Thanks for your interests though.

[Linard Verstraete (linardv)]

Oké, now I understand your point. Please close this bug, like you proposed in your first comment. Thanks for clearing this out for me.