screen brightness is inverted

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Thanks in advance.

There. Hope that helps.

I have seen this too and the behavior seems to have changed recently. Intuitively I noticed something. If I turn the brightness all the way down I see something like what you are referring to. If I leave the keyboard idle, the screen goes to a brighter setting (but not the brightest). If I turn the brightness all the way up, and leave the keyboard idle, it goes to a dimmer setting (but not the dimmest)

Before recent updates:
I think what's happening is something like this. Imagine you have 10 brightness settings from 1-10 with 10 being the brightest and the default. If you leave the keyboard idle for a while it goes to 3. If you had your brightness at the default (or anything higher than 3) then you would see the correct behavior of it getting dimmer. If you happened to have had your brightness at 2 or 1, and left the keyboard idle then going to 3 would actually be brighter.

Most recent versions:
Sometime this past week the behavior seems to have changed as follows. Now it *does* seem to just go to the brightest setting on idle if I had set it at the dimmest. This is quite annoying at night time. I am not sure if this is some kind of wrap-around effect on the brightness setting.

I suspect someone tried to fix this recently and took the wrong approach. What it should do on idle is bring it to the dimmest setting or at least just leave it as dim as the user had it before going idle (not brighter or brightest!).

I can confirm this on Thinkpad T410 with ubuntu 11.10. The way it's happening with me is:

1. Set manually the preferred brightness.
2. Wait some time (usually about 3 secs).
3. press a key or move mouse.
4. Screen goes to full brightness.

I have the power plugged in. This is naturally very annoying. I disabled "Dim screen to save power" checkbox in "Screen settings" to avoid any possible "automatic adjustments" (that was the only related adjustment I found) and it still brings up the brightness to max.

This bug has been reported in association with other bug reports also; marking Confirmed.

I have prepared a PPA test kernel for Ubuntu 11.10 (Oneiric) including a patch which might address the "inverted backlight brightness" problem:

    https://launchpad.net/~kamalmostafa/+archive/inverted-backlight

Feedback to this bug report will be appreciated.

Using Kamal Mostafa's kernel, the brightness behaves normally on my HP Mini, whereas with the latest mainstream kernel update, the bug still existed.

so... does that mean your fix will wend its way into 12.04?

Yes, the fix in the "inverted-brightness" PPA is included in the 12.04 (Precise) kernel.

Indeed, the 12.04 beta 1 (updated) works on my netbook HP Mini.
I've taken the liberty of marking the bug as Fix Committed.

Nope. I still have this issue after installing Ubuntu 12.04 Beta 1. Latest updates.

[Expired for Ubuntu because there has been no activity for 60 days.]

I have prepared a PPA test kernel for Ubuntu 12.04 (Precise) which includes experimental patches that might fix these "inverted backlight brightness" or "backlight off at startup" problems, for laptops with Intel GPU's (despite the name of the PPA, rest assured that the brightness control fixes are not Dell-specific):

    https://launchpad.net/~kamalmostafa/+archive/dellxps

If this test kernel makes your backlight behavior better or worse, please post your results here (reports of "no change" aren't needed).