Athlon Bug Stomper Success Reports for 2.4.14

[Maxwell Spangler]

My Athlon Thunderbird has been happily compiling kernels for over 24 hours
straight using 2.4.14 with an Athlon-optimized kernel.  It could not do this
in many past kernels and I believe the code snippet offered in September is
working nicely.  There was a long thread about this back then, but I haven't
seen any Athlon problem reports between that time and now.  For the lurkers on
the list, and the benefit of archives, could we please record a few successes?

If you are using an Athlon with 2.4.14 and you previously had problems but now
have stability with an Athlon optimized, kernel, please respond.  (Just a few
people, please.)

Oh, hardware is Tyan Trinity KT-A (S2390B) with Athlon Thunderbird 1.2Ghz,
512M Crucial PC133 Cas2 RAM, many drives..etc.

My sincere appreciation and thanks to all that were involved in tracking this
down and making the fix possible.

/*
 * Nobody seems to know what this does. Damn.
 *
 * But it does seem to fix some unspecified problem
 * with 'movntq' copies on Athlons.
 *
 * VIA 8363 chipset:
 *  - bit 7 at offset 0x55: Debug (RW)
 */
static void __init pci_fixup_via_athlon_bug(struct pci_dev *d)
{
  u8 v;
  pci_read_config_byte(d, 0x55, &v);
  if (v & 0x80) {
    printk("Trying to stomp on Athlon bug...\n");
    v &= 0x7f; /* clear bit 55.7 */
    pci_write_config_byte(d, 0x55, v);
  }
}

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Maxwell Spangler
Program Writer
Greenbelt, Maryland, U.S.A.
Washington D.C. Metropolitan Area