[NTLUG:Discuss] Re:nForce2 problems (was Promise Ultra100 TX2...)

[Darin W. Smith]

On Tue, 22 Jul 2003 14:24:09 -0500, Greg Edwards <greg at nas-inet.com> wrote:

> Darin W. Smith wrote:
>> Specifically, what problems have you been having with their graphics 
>> driver?
[snip]
>
> The system is unstable.  It does the Windows thing and just locks up 
> solid ;(  With an ext2 FS it can be a rather unpleasant experience.
>

With ext2, that *can* be *very* unpleasant.  Only my boot partition (1 GB -- 
 overkill) is still ext2.  I converted all the other ext2 partitions into 
ext3 and use reiserfs for a couple other partitions.

Check your syslog for messages like:
kernel: ldt allocation failed

or for vmalloc_32(hex address) failed

These will be symptoms of having too much RAM with the nVidia graphics 
driver and the framebuffer.  Obviously, my guess here doesn't apply if you 
are not using the framebuffer or do not have >512MB RAM.  Chris Cox has had 
this problem as well, and is who pointed me in the right direction.  
Basically, I don't know if disabling the framebuffer will help you as it 
did me, but it is something to try.

However, your symptom (lockups) is much different than what I experienced.  
Mine didn't lockup, just some peripherals wouldn't work and some processes 
would fail to start.

I did a google search and found someone's posting to the kernel development 
list with your exact board.  No replies.  The unfortunate thing is that 
since nVidia's video driver is closed-source and loads a closed-source 
module into the kernel, nobody on the kernel list is going to touch it to 
help.  The kernel becomes tainted with closed-source code, so nVidia are 
the only folks who can really help you debug it (since they have both the 
kernel source and their driver source).  You may wish to email linux- 
bugs at nvidia.com.  If you don't get any results from the main linux-bugs 
email, let me know off-list and I will give you the email of the engineer 
who was helping me for a while.  I don't want to post that guy's email to 
the world.  Caution: the wheels turn slowly in their support department (at 
least, that is my experience).

> Can framebuffer be disabled without rebuilding the kernel?
>

AFAIK, no.  I wish it all played nice together, since the penguin is nice 
(but how often do I boot?  Hardly ever) and there are neat things you can 
do with the framebuffer.  But, I'm doing without it just fine...keeping all 
my memory and running X across two displays off of my dual-output GeForce4 
board.

As I understand it, you are using the built-in nForce graphics.  That is 
essentially a GeForce2, but with one important difference.  I think it uses 
a portion of your system RAM as its video RAM.  So you must make sure you 
have the BIOS setup right, and you may need to exclude that memory from 
Linux.  I don't know for sure, just something I read somewhere at some 
point while looking at boards with that chipset.  I'm going to hold off a 
while before going for an nForce2 board and stick with KT400.

Going googling, it looks like the latest stable kernel, 2.4.21, had some 
fixes for the nForce2.  There apparantly had been some IDE DMA issues.  
I've seen a couple of nForce2 fan sites saying the 2.4.21 support for the 
chipset is pretty solid, so maybe you just need to go up.

I'd suggest going up to 2.4.21, disabling the framebuffer, and making sure 
that you understand where its memory is coming from.  Good Luck, and keep 
us posted.

-- 
D!
Darin W. Smith
AIM: JediGrover
"If you pick up a starving dog and make him prosperous, he will not bite 
you. This is the principal difference between a dog and a man." --Mark 
Twain "Pudd'nhead Wilson's Calendar"