Lenovo R61: Interrupt settings interfere with screen resolution config on amd-64

[Joachim Durchholz]

CONFIGURATION
Lenovo Thinkpad R61 (widescreen model with Nvidia Quadro NVS 140M). Some BIOS settings modified.
RAM upgraded to 4GB (memtest86 ran OK).
Gutsy amd64 CD installed. Initial aptitude update&&aptitude upgrade ritual not yet followed.
Uh... using German translation. English menu titles etc. are guessed. (Can I change the GUI language after the install? There doesn't seem to be a System->Language (System->Sprache) control on the top-left menu.)

PROBLEM
First Gnome start brings up the "System is running in low resolution mode" dialog.
System runs the VESA driver but detects the card as "NVIDIA GeForce 8 Series" (that's all fine by me).
Monitor is detected as Plug 'n' Play, but erreneously offers just 640x480 and 800x600 (and selects the latter, which is good).
Switched to LCD Panel 1680x1050 (that's what the R61 has). Driver still offers just nonmatching resolutions - I forgot what exactly, but the three top entries were 1024x768 and some widescreen resolutions immediately above and below that.
Using one of the top entries would either create the typical I-can-almost-see-what-it-does pixel snow from a wrong pixel count per scan line, or a blank screen. Blank screens would usually go away with Ctrl-Alt-Backspace, sometimes I'd have to Ctrl-Alt-F1 and reboot. There seemed to be a correlation between selected resolution and failure symptoms, but it wasn't consistent enough to report anything for sure.
Trying to select another driver would result in various forms of lockup, or the changes not accepted. (It is a bug if the system reverts/ignores a change without giving a warning. This seems to be a general problem with the screen/graphics settings dialog, though I won't file another bug for that one right now.)

WORKAROUND
After much googling and hair-pulling, is followed an obscure advice, fired up the BIOS settings, Config->PCI setting and switched all interrupts from INT 11 to Automatic.

SPECULATION
I don't have the slightest clue why BIOS-assigned interrupt settings might affect screen resolution settings. Therefore, package assignment was speculative.
I dimly remember that this particular problem did not show up on the 32-bit install that I tried before.

WHAT I CAN DO
I am a competent C programmer. I'm reasonably familiar with the Linux compiler toolchain, though I never learned to use gdb.
I am a competent Linux server administrator. This is my first-time encounter with Gnome.
The machine is destined to become my daily workhorse ASAP. I am willing to try a lot of things short of unfixable breakage and/or reinstalling.

[Joachim Durchholz (jo-kurieradmin)]

Might be unrelated to BIOS interrupts after all.
I had tried a different driver, the machine crashed (as expected), then tried to switch back and got pixel snow and wasn't presented with the proper resolutions. However, rebooting the machine from the Ctrl-Alt-F1 console fixed the problem.

Seems like the hardware retains some state it shouldn't and which gets cleared during a (non-power-cycling) reboot.

[unggnu (unggnu)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This bug did not have a package associated with it, which is important for ensuring that it gets looked at by the proper developers. You can learn more about finding the right package at [WWW] https://wiki.ubuntu.com/Bugs/FindRightPackage. I have classified this bug as a bug in displayconfig-gtk

[davidetkarine (saveurlinux)]

Dear all,
I tryed the 8.04 beta ubuntu using x64 and i did have the same problem for:

Gnome start brings up the "System is running in low resolution mode" dialog.
System runs the VESA driver but detects the card as "NVIDIA GeForce 8 Series" (that's all fine by me).
Monitor is detected as Plug 'n' Play, but erreneously offers just 640x480 and 800x600 (and selects the latter, which is good).
Switched to LCD Panel 1680x1050 (that's what the R61 has). Driver still offers just nonmatching resolutions - I forgot what exactly, but the three top entries were 1024x768 and some widescreen resolutions immediately above and below that.

also I selected the nv drivers but the screen became black.

[Bryce Harrington (bryce)]

Thank you for reporting this bug and for your efforts to make
Ubuntu better. As Xorg has improved this past year, an unfortunate side
effect of these improvements is that it has rendered several design
assumptions in displayconfig-gtk obsolete. So, starting with Hardy we
are no longer putting displayconfig-gtk forth as a primary configuration
tool, and are putting our development focus into the Screen Resolution
applet. As a result, we do not plan to fix this bug and thus are closing
it.

For more background on this change, please see this page:
https://wiki.ubuntu.com/X/DisplayConfigGtk