Corrupt video RAM

Hi,
can anyone suggest what the cause of my corrupt video RAM might be? Just before and just after the login screen my video appears corrupt (I call it a ‘tartan’ screen, but it can be much uglier!). I have an Acer travelmate laptop 2940 running (now) OpenSuse 11.1/KDE 3.5, but I got there after initial difficulties (sound/video/bluetooth) with OpenSuse11.1/KDE4.1 led me to try 11.1/Gnome as well.

I still have difficulties with sound/video and I guess that these are somehow related to the video RAM issue since diverse installations/updates and sound/video configuration adjustments cause a change in the appearance of the ‘tartan’ screen. It seems to me that some part of my linux system is ‘illegally’ using part of the video RAM. Can that be?

Greetings
HN
:\

This has been an issue for kde4 users. It is nothing to worry about - at least not that I am aware of. At times the ‘tartan’ as you call it appears with more definition and clarity - with clearly visible screen images from past sessions. I’m guessing buffered/cached video is responsible - though kde4 must have something to do with it - possibly Plasma related - As I have had vanilla kde3 installs
without these symptoms.

Are you seeing the problem in the framebuffer (boot menu, splash, kdm/gdm) or the X server?

Check in the bios that you have sufficient AGP ram allocated (and if you don’t use AGP, try dropping the allocation or even disabling it), also for anything ISA or OS/2 related and disable that.

And btw, why are you sure that the problem is video RAM?

I have 511MB extended memory and a choice of allocating 64, 128MB or max DVMP (?) for video memory in the BIOS.

I guess the problem is with video RAM because the mess is on the screen! Also if I change the allocation from 64MB to 128MB in BIOS, the tartan mess is different (and, btw, then bluetooth also needs to be re-initialised and the behaviour of the sound system is corrupted). i.e. the behaviour of the sound, video and bluetooth are somehow linked with each other and with the appearance of the tartan mess (which, by the way never looks like past screen images, if that is what was meant).

If other pieces of hardware are affected by these settings, then it sounds like a system memory mapping problem. Once you are logged into KDE or Gnome, does the display problem continue? Also, try enabling DVMP.

A system memory mapping problem is what I suspect. The display problem is visible only shortly before and immediately after the login screen, also when maxDVMT (sic) is enabled (i.e. with any of the available BIOS settings (64MB, 128MB,maxDVMT)). The ‘tartan mess’ is no longer present during normal running of Linux/KDE. The KDE greeting sound is crackled and I can expect problems with embedded video (e.g. youtube, bbcnews etc), MPlayer, Amarok, and USB bluetooth (mouse), but not always. I am pretty sure my hardware is OK.
Often at logout, there is a SIGABRT, but I have no traces enabled (how?)

You could have this problem due to faulty main memory, although I would think you would see other symptoms, and such would be unpredictable. But if wouldn’t hurt to run memtest.

Also, have you checked all the logs? Start with /var/log/boot.msg and the command “dmesg | more” for any errors or warnings thrown by the kernel as it maps memory. Also check the kernel log (/var/log/messages), kdm.log and Xorg.0.log in same directory.

Finally, I would do a firmware check, which will look at your bios. It can be run from the DVD install menu, or from within openSUSE after installing the firmwarekit package.

Memtest? “Command not found”

Not quite sure what I would look for in the logs. I have not found anything particularly illuminating.

The thought occurs to me that it may have something to do with ACPI. My BIOS has no settings for it, and I would not know where to look in the linux system. Any ideas?

These problems arose only with the upgrade to opensuse 11.1. There were no such problems with 11.0/KDE3.5. So, I have no reason to suspect a hardware problem.

Memtest is a program which can be executed from the boot menu that will test your ram; the package is in the repo. It can also be downloaded from its home site and run from a floppy. System builders have used this tool for years; it’s excellent.

You might see the acpi driver throwing errors in the kernel log, /var/boot/messages. Dmesg may show some errors, e.g., if the bios does not support acpi (bios setup not showing acpi settings doesn’t mean its not there). There are a number of tools in the repo for viewing the acpi tables (acpiw, pmtools) and firmwarekit (an Intel bios testing program) will check the tables - you might be surprised at how often bios acpi implementations are flakey.

I would also wonder about your video driver. You might check into a different version. Also, just give this a try in Boot Options:

edd=off acpi=off

edd=off acpi=off results in: tartan mess at login, bad sound, good usb bluetooth plus (new) no wlan.

The graphics card is given by SaX2 “Intel 945 GM”. However, the laptop handbook refers to “Intel 943/940 GML Express Chipset” for this model. How to I go about finding/using another driver in this case?

:open_mouth:

AFAIK, it’s the same driver. There have been issues with this driver especially on laptops; search the forums here. This is not to say that such is your problem, though. I would test the vesa driver to see if you get the same issue. You may not be able to get your native resolution with vesa, but switching temporarily might help isolate the problem to the driver.

When you switched to Gnome or KDE 3.5, did you do so as a clean install?

If not, I’m guessing you’re still using KDM-kde4 as your display manager. This problem was reported with the newer nvidia drivers and KDE4, but could be a generic issue with KDE4 and the graphics handling. You may want to switch to KDM-kde3, just to see if the problem still exists.

You simply need to make sure you have kdebase3-kdm installed, and then make a simple change via Yast /etc/sysconfig.

Yast -> System -> /etc/sysconfig

Select Desktop -> Display Manager -> DISPLAYMANAGER and set the value to kdm.

(ok, maybe “simple” is a bit of a stretch, but it’s straight-forward)

kdm3 will still allow you to log in to KDE4 (or Gnome). In fact, I’m using it right now with KDE 4.2 because KDM4 doesn’t seem to like the new Qt libraries.

Of course, if you’re already using kdm3 (or GDM), then feel free to ignore this post.

Anyways, just a thought…

Cheers,
KV

Big kiss for else_where! :slight_smile:

kdebase3-kdm needed to be installed plus DISPLAYMANAGER setting. The “tartan mess” has gone.

Now though my bluetooth (mouse) via usb dongle needs a kickstart after every boot (monitor scan and configuration) AND the sound is still scratchy at login. I have only tried BBC embedded videos and they (sound and video) seem to work (apart from a funny digital buzz sound just after starting to play). I guess it is still linked with the fact that I did not do a very clean kde3.5 install.

Any ideas?

There’s @else_where coming to the rescue again. :slight_smile:

As far as the sound problem: I suggest you open a new thread under the hardware or perhaps multimedia sub-forum. You’ll get faster/better response than on this older, differently titled thread. Before doing that however, in KDE 3 go to Personal Settings (KControl) and check your settings under Sound. Try enabling the Skip Prevention, check under Hardware that you are using Alsa (or try switching it to OSS and see if that makes a difference); you may need to logout/in to test the effects (not reboot, just out/in of KDE). Also, if you search the forums, you’ll find a couple very good write-ups on testing sound. This isn’t my area of expertise, so I’m afraid that’s all I have to offer on this one.

After the tip about a clean kde3.5 installation from else_where, I decided to check for other remnants of kde4 in my installation and ditched them. The whole thing is beginning to look very promising. Unless I stumble on anything else which annoys me, I’ll regard my problem as solved!! Many thanks to you great gurus!:slight_smile:

You’re very welcome - although the credit is due to @else_where. :slight_smile:

I’m almost sure we’re talking NVidia cards…There’s a lot about this in their fora, has to do with mix of driver versions