Re: another Cyrix/mtrr problem?

[David Wragg]

[e-mail] (Bob_Tracy) writes:
> Unfortunately, when I execute
> 
> echo "base=0xd8000000 size=0x100000 type=write-combining" >| /proc/mtrr
> 
> I get a 2MB region instead of the 1MB region I expected...

Oops, it got broken by the MTRR >32-bit support in 2.4.0-testX.  The
patch below should fix it.

Joerg, I think this might well fix your Cyrix mtrr problem also.

Let me know how it goes,
Dave Wragg

diff -uar linux-2.4.2/arch/i386/kernel/mtrr.c linux-2.4.2.cyrix/arch/i386/kernel/mtrr.c
--- linux-2.4.2/arch/i386/kernel/mtrr.c	Thu Feb 22 15:24:53 2001
+++ linux-2.4.2.cyrix/arch/i386/kernel/mtrr.c	Wed Mar 14 22:28:02 2001
@@ -538,7 +538,7 @@
      * Note: shift==0xf means 4G, this is unsupported.
      */
     if (shift)
-      *size = (reg < 7 ? 0x1UL : 0x40UL) << shift;
+      *size = (reg < 7 ? 0x1UL : 0x40UL) << (shift - 1);
     else
       *size = 0;