flickering Monitor

English Hardware
1

For many years I was running a Hanns-G monitor. It used to flicker a little bit sometimes. But not in large extent.
Now I’ve got a ussed Acer B223w. I connected it via VGA cable (no DVI port on my on-board graphic system).
The system recognized the model correctly.
But the monitor produces a flickering that is barely tolerable.

I’ve read around a bit in the forum. Only found found something of earlier Suse versions.
Something was written about x.org.conf.
I found the monitor specs on https://www.manualslib.com/manual/233060/Acer-B223w.html?page=5#manual

But when I add the mentioned rates into my /etc/X11/xorg.conf.d/50-monitor.conf file
the system doesn’t mount properly. It ends up on console without xserver.

Maybe I don’t understand the xorg concept properly. My conf file looks as follows:


#Section "Monitor"
#  Identifier "Default Monitor"
#
#  ## If your monitor doesn't support DDC you may override the
#  ## defaults here
HorizSync 30-80
VertRefresh 55-75 

#
#  ## Add your mode lines here, use e.g the cvt tool
#
#EndSection

Do I have to add more than just the two unhashed lines?

2

OK, I removed some more # and it booted completely.

I like to imagined the flickering to have become a little bit better. But not sure yet.

3

No. It’s bad as it was before…

In the aforementioned specs I found the resolution to be 1280x1024@60Hz.
And I have to say it’s indeed better then with 1680x1050. But that’s not a suitable resolution because everything is desplayed wider than it should. Circles are ellipses.
How come a monitor producer distributing specs that don’t fit the dimension of the screen? That’s strange.

Any idea?

In the Hardware Informations (yast) under Monitor > Display I also found given frequencies different from those I entered into /etc/X11/xorg.conf.d/50-monitor.conf .
Maybe there’s still something missing in my conf file, so that my values don’t accurately override these other values?

/etc/X11/xorg.conf.d/50-monitor.conf looks like this atm:


# Having multiple "Monitor" sections is known to be problematic. Make
# sure you don't have in use another one laying around e.g. in another
# xorg.conf.d file or even a generic xorg.conf file. More details can
# be found in https://bugs.freedesktop.org/show_bug.cgi?id=32430.
#
Section "Monitor"
  Identifier "Default Monitor"
#
#  ## If your monitor doesn't support DDC you may override the
#  ## defaults here
HorizSync 30-80
VertRefresh 55-75 

#
#  ## Add your mode lines here, use e.g the cvt tool
#
EndSection

Of course there might be other reasons for the flickering. I already tried turning of the PC speakers and my mobile phone, without success. Could be even something from my neighbours. But I like to eliminate all software causes before changing the RL environment.

4

What does booting through the Advanced Options do? Any other monitor available to test? What desktop environment? What’s the onboard video chip?

5

Advanced options only offer 4 ways of booting:

  • Leap 42.2, with Linux 4.4.79-18.26-default <— that’s what I’m also booting usually
  • Leap 42.2, with Linux 4.4.79-18.26-default (recovery mode)
  • Leap 42.2, with Linux 4.4.73-18.17-default
  • Leap 42.2, with Linux 4.4.73-18.17-default (recovery mode)

doesn’t appear so advanced to me…

Another monitor:
I was running a Hanns-G before. It was flickering, too. But not to that extent. It was bearable.

But I installed openSUSE with the Hanns-G connected. Maybe I have somehow some settings running that were fitting to the Hanns-G, but not the Acer (?).

Video chip:
Yast > Hardware Info > Display > 965G :


Bus: PCI
Class (spec): VGA-compatible controller
Class: Display Controller
Device Identifier (spec): 94785
Device Identifier: 76194
Device: 965G
Driver: i915
Hwcfg Bus: pci
Kernel Driver: drm
Model: Intel 965G
Old Unique Key: 
> Resoruces ...
Revision: 2
Slot ID: 2
Subvendor Identifier: 70754
Subvendor: Micro-Star International Co., Ltd. [MSI]
...
...
> x11
>> intel
>>> Version: 4
>>> server: intel
>> intel
>>>> extensions: dri
>>> has_3d: Yes
>>> server: intel

I had to type it all by hand, since I found no way to copy&paste it. So I left out some entries that seemed to be of less interest.

6

As a test I booted the third entry. The flickering stays the same.

7

I don’t think playing with the display resolution will help here. This is largely automatic these days anyway. No need to edit Xorg configuration files.

FWIW, there are a few bug reports describing this behaviour…
https://bugs.freedesktop.org/show_bug.cgi?id=95010
https://bugs.freedesktop.org/show_bug.cgi?id=101586

Some users report using the following kernel boot parameter helps as a workaround…

i915.enable_rc6=0
8

I had to type it all by hand, since I found no way to copy&paste it. So I left out some entries that seemed to be of less interest.

Use the hwinfo command…

/usr/sbin/hwinfo --gfxcard
9

Thank you!

Unfortunately that boot option doesn’t help.
I put on my old monitor to get rid of the flickering.
I’m almost sure now it’s no software issue. It must be the Acer itself (sometimes the problem started even before grub showed up).
Although other tests are still pending.