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dark screen in current [SOLVED]
Posted: 21. Apr 2010, 17:32
by lipk
Hi,
I've just switched to current, and I'd prefer it to 13.0, but I have a big problem:
Since I firstly suspended the machine, the screen got dark; even reboot didn't help (BIOS splash's also dark!!). I had had this problem with almost all distros I've tried so far (the only exception is SUSE, which could not suspend at all

), and there ACPI was the guilty doubtlessly (how strange....). The solution was to play a bit with the "Screen brightness" slide in the power manager application, but I couldn't find any option like that in the Xfce power-manager.
Help please, this dark screen makes me depressed

Re: dark screen in current
Posted: 21. Apr 2010, 18:06
by thenktor
Notebook or desktop TFT?
Try the command line tool xbacklight.
Re: dark screen in current
Posted: 21. Apr 2010, 18:25
by lipk
notebook.
xbacklight does nothing... xbacklight -get or -steps n says "no outputs have backlight property", -dec or -inc don't have any noticeable result.
But I caught an error message during boot:
Code: Select all
ACPI I/O resource (number) [address] confilcts ACPI region SMBI [address]
Re: dark screen in current
Posted: 21. Apr 2010, 18:38
by gapan
xfce4-power-manager includes a brightness panel plugin. Did you try to add that to your panel and use it?
Re: dark screen in current
Posted: 21. Apr 2010, 18:49
by lipk
Yes, it works. Thanks a lot!!! Is there any way to control it from the command line?
Re: dark screen in current
Posted: 21. Apr 2010, 19:51
by gapan
Not really sure, but try to find a brightness file in your /proc/acpi/video/...
and try to echo a value to it:
Code: Select all
echo -n 50 > /proc/acpi/video/VGA/LCD/brightness
for example.
Re: dark screen in current
Posted: 22. Apr 2010, 16:28
by lipk
It works. Thanks, gapan!
Re: dark screen in current [SOLVED]
Posted: 22. Apr 2010, 18:37
by klanger
I have similar problem, but with my eeepc running live-cd (with remembered settings).
Every time eeepc suspends, it can't wake up - the little hdd-led indicates disk writes (even though system is on usb-stick) but nothing happends, just black screen (no way to jump out of X) & no keyboard working - only power-off button works OK.
I've 2GB RAM & and live-cd is on 2GB USB-stick could that be a problem (when I had 1 GB RAM once or twice it has suspended corectly).
edit:
problem is solved - it is the RAM problem - with 1GB of RAM eeepc suspends&resumes correctly
probally my usb-stick is too small (only 2GB) for 2GB RAM...
Re: dark screen in current [SOLVED]
Posted: 22. Apr 2010, 21:20
by Shador
klanger wrote:problem is solved - it is the RAM problem - with 1GB of RAM eeepc suspends&resumes correctly

probally my usb-stick is too small (only 2GB) for 2GB RAM...
To my knowledge it only depends on swap space. The live cd usually tries to enable all swap partitions available. When hibernating the ?biggest? one is chosen for hibernate. Generally it's recommended for hibernate to have a swap partition 130% the size of the available RAM. Though anything from 100% on could work.
I used to think hibernate would just abort if there isn't sufficient memory, but it seems to be kind of unpredictable. I just tried and it aborted but also restarted X.
Anyway this can be quite nasty. If memory is full and swap is used additionally (i.e. not anymore enough space for hibernate) it already occurred to me that I hibernated my laptop and directly put it into my bag. Some time later I take it out again realizing by the warmness of the case that it had been up a while before running out of battery.
Also some applications like VirtualBox can have very weird results.
Re: dark screen in current [SOLVED]
Posted: 23. Apr 2010, 04:56
by klanger
Thanks Shador.
I don't have swap on usb-stick (salix-live) & I don't use hibernate (it doesn't work probably due to no swap). Suspend with 1GB of RAM and 2GB usb-stick works like a dream though
It is not the most needed feature in an OS for me, but since it worked earlier it is nice that it works now.