From: Jon M. Taylor <taylorj@ecs.csus.edu>
  To  : ggi-develop@eskimo.com
  Date: Mon, 6 Jul 1998 18:52:46 -0700 (PDT)

Re: kgicon: Unable to handle kernel paging request...

On Mon, 6 Jul 1998 jonas_b@bitsmart.com wrote:

> Hi,
> 
> I have a problem with kgicon..
> 
> The kernel pukes with:
> 
> Unable to handle kernel paging request at virtual address 5b1b4834
> current->tss.cr3 = 0372c000, %cr3 = 0372c000
> * pde = 00000000
> Oops : 0000
> ....
> ....
> Call Trace [c019300e>] [<c018a687>]......
> 
> And con_put_char is at address c0192ff0, so it's there somewhere.
> Has anyone who has tested the kgicon with another driver than Matrox seen
> this error message. Maybe it's a bug in the Matrox code?
> 
> I'll get this message every time I run 'man gcc' and press down arrow a few
> times and then press the up arrows a few times.
> 
> Any ideas?

	I've seen an occasional oops with Lynx and now that I recall it
did happen with scrolling up and down.  I suspect fbcon bugs - the current
kgicon does not use ywrap to scroll, which makes things quite a bit slower
and every once in a while if I push it hard I can see the cursor square
end up on a scrolled up-line.  This implies synchronization problems, and
if that happened on the top line of the display the bad cursor might get
written to the previous line, which would be off the bottom of the
framebuffer in an invalid memory address and would generate an oops like
described above.  Geert and Martin Mares have fixed quite a few fbcon bugs
in their latest patches, so either get those or wait for the next kernel
release and let's see if that fixes the problems. 

Jon

---
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