No Backlight Control in 2.2.18pre21

No Backlight Control in 2.2.18pre21

[Derek Homeier]

Subject says it: with current linux-pmac-stable kernels, the backlight
control via [Fn-]F{1,2} does not work, neither dimming nor turning off
the LCD altogether, on a PB Lombard at least.
Might have been this way since the CONFIG_PMAC section appeared, in any
case, in 2.4.0-test11 there is a CONFIG_PMAC_BACKLIGHT option, and backlight
control is working (I've set it to "=y", of course).
It also seems that my PB suffers very frequently from increased battery
discharge during sleep, but I can't note any difference here between
-stable, -benh and -devel.

Cheers,
							Derek


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Re: No Backlight Control in 2.2.18pre21

[Simon Stapleton]

> Subject says it: with current linux-pmac-stable kernels, the
> backlight control via [Fn-]F{1,2} does not work, neither
> dimming nor turning off the LCD altogether, on a PB Lombard
> at least.
> Might have been this way since the CONFIG_PMAC section appeared,
> in any case, in 2.4.0-test11 there is a CONFIG_PMAC_BACKLIGHT
> option, and backlight control is working (I've set it to "=y",
> of course).

Funny you should mention this.  I was about to pen a missive along
the same lines.  I noticed it this very weekend when getting back
to hacking together ADB Wacom support (not necessarily coming
any time soon, BTW)

The problem appears, to me at least, that if you use the USB
backport code the powerbook buttons stuff doesn't get included.
I think somewhere a CONFIG_PMAC_BACKLIGHT is being missed, but
I may well be wrong.  Changing CONFIG_PMAC_BACKLIGHT to
CONFIG_PMAC_PBOOK seems to fix the problem (and seems to make
more sense as we're dealing with powerbook button devices here.
Or are we?  What about the buttons on the front of some of the
older pmacs, and on the apple monitors?  I assume these are all
ADB devices.  I can't test the monitor stuff as my 1710 decided
it doesn't want to start up recently.  Bah.)

In a related note, I've been looking at the code that does this.
I had a patch under 2.2.17 to make the volume and mute buttons work
on my wallstreet, and was wanting to reinstate it - the original
patch won't work but the coding seems (relatively) simple.

So - a couple of questions.

1: What is labelled as the 'contrast' button is actually the
   wallstreet volume control.  Is this the case for other Pbooks?
   (I can probably get hold of a 3400 to test, but kangas, lombards
   and the like are all unreachable).  If this _is_ the case, could
   we rename the constant?
2: Getting to the sound device.  This is probably a stupid question,
   but here goes anyway... The sound device is controllable from
   userland via the /dev/mixer ioctl, as far as I can see.  Can I
   use this from within the kernel, or is that a big no-no?  I don't
   like the idea of putting extra helpers in the sound code (or even
   using existing ones directly), as there's no guarantee that sound
   support has been built in.  And I _really_ don't like lots more
   #ifdef's in the code.

Thoughts, comments, flames?

Simon

--
Your mouse has moved.  You must reboot Windows NT for these changes to be
recognised.


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Re: No Backlight Control in 2.2.18pre21

[jpgarcia, UNEXPECTED_DATA_AFTER_ADDRESS]

On  4 Dec, Simon Stapleton wrote:
> Thoughts, comments, flames?

http://www.execpc.com/~jpgarcia/sys.html

at the above URL, i have some links to kernel patches.  One is a patch
to implement new input layer support for the volume/mute buttons using
 a similar method to the backlight controls. The 2.4 version I wrote is
 incomplete, and the 2.2 version uses the 2.4 dmasound backport.  An
 older one is more of an update from a patch that was posted to this
 list months ago.

The new layer one also tries to feature NIL volume keys (they're in the
header), but I don't think I did it right.

Beware, I consider these patches to be 'my personal stash', and are
rather messy in places.

If anyone wants me to work on them more, or work on them themselves,
just say so.

My standing is, the buttons are there, lets use them.  iBooks and
Pismos still have them built into the keyboard too.  Do we want these
controlled kernel level, or send a keystroke so X (or something else)
can catch it?  If I can get to fixing the newer 2.2 patch, it could do
either way.

--
Joseph P. Garcia
http://www.execpc.com/~jpgarcia


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Re: No Backlight Control in 2.2.18pre21

[Simon Stapleton]

Quoting jpgarcia@execpc.com,UNEXPECTED_DATA_AFTER_ADDRESS@.SYNTAX-ERROR:

> http://www.execpc.com/~jpgarcia/sys.html
>
> at the above URL, i have some links to kernel patches.  One is a
> patch to implement new input layer support for the volume/mute
> buttons using a similar method to the backlight controls. The
> 2.4 version I wrote is incomplete, and the 2.2 version uses the
> 2.4 dmasound backport.
> An older one is more of an update from a patch that was posted
> to this list months ago.

Rock! I'll give this a go tonight.  I think it's probably worth
trying to get this cleaned up and approved for a 'official' release.

> The new layer one also tries to feature NIL volume keys (they're
> in the header), but I don't think I did it right.
>
> Beware, I consider these patches to be 'my personal stash', and
> are rather messy in places.
>
> If anyone wants me to work on them more, or work on them
> themselves, just say so.

If you need any hands to the pumps, or someone to look over changes,
let me know.  Unfortunately our machines appear to be very similar,
but, as I said, I have access to a 3400.  I should also be able to
get to a firewire pbook 500 in a week or so.

> My standing is, the buttons are there, lets use them.  iBooks and
> Pismos still have them built into the keyboard too.

Aye to that.

> Do we want these controlled kernel level, or send a keystroke so
> X (or something else) can catch it?  If I can get to fixing the
> newer 2.2 patch, it could do either way.

My vote is for kernel level.  Having a volume control daemon or the
like seems very kludgy, IMHO.

A thought occurs to me, though.  A friend of mine recently bought
an I86 laptop wich has a bunch of 'shopping' buttons built in.  Are
these supported in Linux, and if so, what's the mechanism used?

Simon

--
Your mouse has moved.  You must reboot Windows NT for these changes to be
recognised.


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Re: No Backlight Control in 2.2.18pre21

[Benjamin Herrenschmidt]

>1: What is labelled as the 'contrast' button is actually the
>   wallstreet volume control.  Is this the case for other Pbooks?
>   (I can probably get hold of a 3400 to test, but kangas, lombards
>   and the like are all unreachable).  If this _is_ the case, could
>   we rename the constant?

Some wallstreet with passive matrix display also have a contrast button
(and contrast setting via the PMU). I found some infos about those and a
friend with such a machine to test with, I'll try to get something out if
I find some time.


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