[SOLVED] vesafb and mtrr

atdsm · Posted: Tue Feb 07, 2006 11:36 pm Post subject: [SOLVED] vesafb and mtrr

Hi all,

I'm having the following problem:

After X starts, all my virtual consoles outside of X are blank when I switch to them with CTRL+ALT+F[1-6]. (Before X starts they are not.) They are in fact not only blank, but also not sending any video to my monitor. I know this because my LCD monitor reports that the signal is out of range.

Here's some background:

I just updated to a 2.6.15 kernel (2.6.15-gentoo-r1). vesafb-tng is built in to the new kernel, nvidiafb is not. Because I have read numerous places that the stable nvidia-kernel package doesn't work with newer kernel sources, I emerged the testing version (1.0.8178-r3) of nvidia-kernel and nvidia-glx. I also reemreged splash-utils and redid all my fbsplash stuff. I rebooted to my new kernel, and framebuffer and splash work great. I have a nice big gentoo "g" on the background of my consoles. I can also switch around to all the consoles using CTRL+ALT+F[1-6]. I can also fire up the X server (Xorg 6.8.2-r6, fluxbox), and everything in X works great as well. BUT, after that if I switch to a console using CTRL+ALT+F[1-6] I get the blank screen reported above.

What I think might be the problem

One thing I didn't do was update my grub.conf lines for fbsplash and vesa-tng. Here is what my grub.conf looks like (an excerpt):

_loki_ · l33t Joined: 18 Dec 2003 Posts: 680 Location: in the shell

have a look on /usr/src/linux/Documentation/fb/vesafb.txt

atdsm · Posted: Wed Feb 08, 2006 12:35 pm Post subject:

Thanks!

Hmm... this is strange.

marcusvini · n00b Joined: 30 Nov 2005 Posts: 22 Location: Brazil

from our Gentoo Linux nVidia Guide

_loki_ · l33t Joined: 18 Dec 2003 Posts: 680 Location: in the shell

this is abozt framebuffer and shouldn't be related to nvidia-kernel module.. Did you try all options? When I run

atdsm · Posted: Wed Feb 08, 2006 10:48 pm Post subject:

Ok, let's see, I have several replies to make here...

First, marcusvini, I don't have an integrated MX card... I have an MX 400. It's still supported by the new drivers (8178). I know this because it's on the list at nvidia's website: http://www.nvidia.com/object/IO_18897.html

Besides, my nvidia driver is working great... its the vesa framebuffer driver that isn't.

Second, I tried "mtrr:2" again, and it definitely gave me the same problem: a slow updating screen that updates only a few scattered lines at a time over several seconds. There is also a 1-2 second delay before any typed characters begin to be echoed to the screen (and then they come in piecemeal). "mtrr:1" works, but it doesn't solve my X and VT problem.

Third, loki, I would try "mtrr:3" (write-combining) for you, based on your /proc/mtrr output. Dunno if that will solve anything though.

I'm going to have a look through the vesa documentation that loki helpfully provided the path to, and see if I can find anything else.
_________________
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atdsm · Posted: Wed Feb 08, 2006 11:03 pm Post subject:

Ah! I found the magic bullet. First off, though, both "mtrr:1" and "mtrr:3" seem to work for me, and "mtrr:2" doesn't, which is counterintuitive to me, but whatever. Moral: just try stuff to see if it works.

So... the magic bullet. I found the following useful information in vesafb.txt:

Anchialus · n00b Joined: 07 Mar 2005 Posts: 19

Okay, this almost solves all of my problems. I also couldn't switch between X and console, until I put "nocrtc" in the grub boot options. Now, I can switch with no problems.

However, when I leave X, my console does not come back. I get a blank screen, it doesn't matter which console I try to get to (using alt+[1-6]). There is some kind of signal coming to the monitor, as it doesn't go into "low power" mode like it has done before.

Do you have this problem? I suppose I could just never shutdown X after I start it, but I don't like this solution.

_loki_ · l33t Joined: 18 Dec 2003 Posts: 680 Location: in the shell

do you use nvidia kernel module?

Anchialus · n00b Joined: 07 Mar 2005 Posts: 19

_loki_ · l33t Joined: 18 Dec 2003 Posts: 680 Location: in the shell

nvidia kernel module doesn't like the framebuffer and keeps killing it (for me) when I quit X.. Doesn't know about the ati though never heard that kind of behaviour for that..

assaf · Posted: Fri Feb 10, 2006 7:39 pm Post subject:

I have both the vt-switching problem and the freeze when shutting down x problem. I've tried the mtrr:3 and nocrtc, and they didn't help. Switching to the nv driver or disabling the framebuffer solves the problem (had to patch vesafb_tng to add an off option because I couldn't figure out another way to disable it :evil:

).

I'm not sure what causes the problem because I've upgraded both the kernel and the nvidia-kernel driver recently (and I don't leave X most of the time). It used to work fine with 2.6.12-r10 (not sure about the exact nvidia version), doesn't work with 2.6.15-r1 and 8178-r3.

_loki_ · l33t Joined: 18 Dec 2003 Posts: 680 Location: in the shell

it never worked for me the last two years!!!

Anchialus · n00b Joined: 07 Mar 2005 Posts: 19

I have to say that this is very discouraging. I suppose I'll just have to never leave X once I've gone in.

Something interesting that may help the ATi side of things:

I killed X from a virtual terminal, and got this:

assaf · Posted: Fri Feb 10, 2006 10:10 pm Post subject:

I get something of this sort in the system log: