udev causing "Cannot Display the Video Mode" on flat panel

[Kam Leo]

On 5/1/07, Edward DeMeulle <ed at demeulle.org> wrote:
> On 5/1/07 19:27, Kam Leo wrote:
> > On 5/1/07, Edward DeMeulle <ed at demeulle.org> wrote:
> >> On 5/1/07 10:17, Mikkel L. Ellertson wrote:
> >> > Edward DeMeulle wrote:
> >> >
> >> >> After fresh installing Fedora 6 just after udev starts the screen
> >> goes
> >> >> blank and displays the above message. Neither setting runlevel 3
> >> in GRUB
> >> >> nor Ctrl-Alt-F1,F2, etc. restore the screen. I do have ssh access and
> >> >> can even do Ctrl-Alt-F1 and blindly login. So now what? Apparently
> >> udev
> >> >> is either causing the video card to set itself to an unusual mode or
> >> >> it's forcing it to use the DVI port (I'm bringing a cable home to
> >> test
> >> >> this, but I want to use VGA for my KVM switch). Video card is an ATI
> >> >> Rage 128. I've read through the udev literature for a bit and am
> >> trying
> >> >> to understand it's workings. Does anyone have any tips that might
> >> speed
> >> >> up the resolution of this problem?
> >> >>
> >> >>
> >> > First off, it is probably not udev causing the problem. A quick test
> >> > would be to boot without rhgb in the boot line. This will keep
> >> > things in the text mood on boot, instead of the pretty graphical
> >> > boot display. When you edit the grub line to remove "rhgb", you may
> >> > also want to put a 3 at the end so you boot in the text mode. Then
> >> > try configuring X again.
> >> >
> >> > Mikkel
> >> >
> >> I tried what you suggested. However, the video mode is still getting
> >> messed up and causing the above message from the flat panel right after
> >> the "Starting udev" message. Following is the grub entry being used:
> >>
> >> title Fedora Core (2.6.18-1.2798.fc6) Text
> >>         root (hd0,0)
> >>         kernel /vmlinuz-2.6.18-1.2798.fc6
> >> root=/dev/VolGroup00/LogVol00 3
> >
> > Append "vga=791" to the above line. It should set the graphics adapter
> > to 1024x768x64K colors.
> >
> >>         initrd /initrd-2.6.18-1.2798.fc6.img
> >>
> >> --
> >> Edward DeMeulle <ed at demeulle.org>
> >
> That got me back the screen. Thanks! Why does it turn out that both of
> these lines result in a text boot-up (no pretty boot display)? I tried
> vga=normal as well as vga=extended. It seems that for some reason the
> video needs to be set to a graphics mode or udev trashes it. Does this
> make sense?

You will have to ask the Grub/Xorg experts.

>
> kernel /vmlinuz-2.6.18-1.2798.fc6 root=/dev/VolGroup00/LogVol00 vga=791 3
>
> kernel /vmlinuz-2.6.18-1.2798.fc6 root=/dev/VolGroup00/LogVol00 vga=791
> rhgb quiet

Is there any reason you want to mask the status of the booting
process? I, personally, find with the constant churning of packages
that "rhgb" and "quiet" get more in the way than help.

> --
> Edward DeMeulle <ed at demeulle.org>