https://bugs.kde.org/show_bug.cgi?id=312634
Bug ID: 312634
Summary: Screen won't wake up after blanking
Classification: Unclassified
Product: kde
Version: 4.9
Hardware: Other
OS: Linux
Status: UNCONFIRMED
Severity: major
Priority: NOR
Component: general
Assignee: unassigned-bugs at kde.org
Reporter: alpheus.madsen at gmail.com
I am using Kubuntu Linux 12.10. I installed the system on a Dell Latitude
E6530 Laptop three days ago (Wed, 2 Jan 2012), and updated the system this
morning. When the system monitors blank out after a period of time, whether it
be because I lock the screen using Ctrl-Alt-L, or whether the screen just times
out, when I try to wake up the screen, the laptop monitor remains blank. I do
notice a "brightening" of the black screen, but nothing else happens.
At first, I thought it was strictly a "wakeup" problem, but now that I have a
second (VGA) monitor plugged in, the bug remains, but *only* affects the laptop
monitor. Since at one point I was using ssh to transfer files from an older
laptop to this one, I also know that the computer doesn't just "lock up" during
this time, but the screen just isn't working. (Oh, heck, this is obvious:
I'm using the computer right now with a blank laptop screen.) I can move
program windows to the other screen,
At one point, I thought that I couldn't launch RandR, but what probably happens
is that it opens on the laptop screen rather than the main screen--I like to
have my Task Manager show only files on current screen and desktop--and I find
if I clone my screen, the windows are pushed onto the monitor that works; thus,
it seems that KDE still recognises the existence of the screen, even when the
screen isn't displaying anything.
If I restart the computer, the laptop monitor will work normally again; and
will usually go through several locks or "naps" before the problem comes back.
So far, it's happened at least two or three times a day.
Apparently, the Dell Latitude E6430 has been known to have problems with USB
3.0 ports (see http://brianmorristech.com/?p=953), so perhaps this might be the
problem; I do not know how to disable USB 3.0, though, and plugging a mouse in
the 2.x port (and later, a wireless mouse and keyboard dongle) doesn't seem to
prevent the problem. On the other hand, I also plug in the mouse's charger in
one of the other 3.0 ports... Having said that, keep in mind that the problem
described in the link is a Windows issue as well, so it might not be applicable
to Linux.
I also do not know how "sleep" and "hibernate" affect this bug. I haven't been
putting my laptop to sleep; I have only put the laptop in hibernation once, via
"pm-hibernate", to test that it works. (My swap is 33G, since I wanted to make
sure there was plenty of room for the 16G of RAM I had, and I wasn't sure
exactly how big the swap needed to be; perhaps that's another issue that ought
to be addressed, but that's an installer thing...)
Reproducible: Sometimes
Steps to Reproduce:
1. Install Kubuntu Linux with swap on a Dell Latitude E6530
2. Lock the screen, and/or let the screen go blank on its own without locking
it.
3. Repeat #2 several times. Eventually the monitor won't display anything, I
think.
Actual Results:
At some point, the laptop monitor will be black--maybe brighten a tiny bit--and
won't display anything.
Expected Results:
The unlock dialog should have popped up, or in the case of just blanking the
screen, the original screen should have come up instead.
I chose "Major" because while under certain conditions the laptop is useful
without the problem (I can use an external monitor, for example, and if I get a
second, I probably won't notice it), it would be a pretty horrendous problem if
I had to travel, and in the process of using my computer, I had to reset my
computer on a regular basis, I'd be able to do some stuff, but it would be
highly annoying.
I would add that this is almost a "Grave" problem.
Also. I apologise for any horrendousness in my bug description. I am a native
English speaker, after all...
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