mactel-support team mailing list archive

[Luke Gumbley <l.gumbley@xxxxxxxxxxxxxx>]

I have had the same problem with my MB5.1.  I resolved it by reverting
to an old version with the following steps:

1. Set the dkms status of nvidia_bl to uninstalled:

sudo dkms uninstall -m nvidia_bl -v 0.16.1

2. Delete the dkms build directory for nvidia_bl (your kernel version
may differ)

sudo rm -r /var/lib/dkms/nvidia_bl/0.16.1/2.6.31-20-generic

3. Replace the source with an older version (I've attached one that I
found works, see below)

sudo cp ~/nvidia_bl.c /usr/src/nvidia_bl-0.16.1/

4. Rebuild using dkms

sudo dkms build -m nvidia_bl -v 0.16.1

5. Install using dkms

sudo dkms install -m nvidia_bl -v 0.16.1

6. Restart your computer.  I found that simply rmmod/modprobing
nvidia_bl was not sufficient to make it fully work, I had to restart.
Hooray, you can now work without being blinded.

The version of nvidia_bl.c that I attached is supposedly from version 0.15.4, courtesy of this page:
http://aur.archlinux.org/packages.php?ID=25467

I chose 0.15.4 because a) I could find it and b) as there have been a
flurry of changes lately which 0.15.4 seemed to precede.

You could possibly also revert nvidia_bl.c using the patches in the
'patches' subdirectory.  I tried all of those and they all compiled
successfully, but nvidia_bl.c contains no module version information and
I couldn't be bothered restarting half a dozen times to test, so I
settled on trying the independent 0.15.4 source that I attached.  I did
try rmmod/modprobing them but none worked, I suspect the new 0.16.1
module stuffs up the registers on startup, after which even correct
drivers won't work.

It would be very useful if the preceding version was kept in the
repository instead of replacing on upgrade, or even if several old
versions could be kept.  The package is only 60k, and it means that you
can revert properly with synaptic instead of all this console hack-
fixing.

-- 
nvidia-bl-dkms 0.16.1 breaks screen brightness (backlight) adjustment on MacBook 5.1 [Karmic]
https://bugs.launchpad.net/bugs/538326
You received this bug notification because you are a member of Mactel
Support, which is the registrant for Mactel Support.

Status in Mactel Support: New

Bug description:
On my MacBook 5.1, upon updating to nvidia-bl-dkms 0.16.1~karmic, the brightness controls fail to have physical effect on the brightness of the screen. The screen brightness remains at 100% brightness.

Pressing the brightness keys brings up the brightness indicator in the notifications area, and cause the brightness bar to move up or down very slowly (see Bug #357112), however this has no effect on physical brightness. Similarly, using the slider under System -> Preferences -> Power Management has no effect on physical brightness.

This is a severe regression. The 0.15 series was annoyingly slow to respond, but this new series doesn't respond at all.