linux/arch/i386/kernel/acpi/earlyquirk.c
Chuck Ebbert 66759a01ad [PATCH] x86-64: i386/x86-64: Fix time going twice as fast problem on ATI Xpress chipsets
Original patch from Bertro Simul

This is probably still not quite correct, but seems to be
the best solution so far.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-12 10:50:58 -07:00

59 lines
1.3 KiB
C

/*
* Do early PCI probing for bug detection when the main PCI subsystem is
* not up yet.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <asm/pci-direct.h>
#include <asm/acpi.h>
static int __init check_bridge(int vendor, int device)
{
/* According to Nvidia all timer overrides are bogus. Just ignore
them all. */
if (vendor == PCI_VENDOR_ID_NVIDIA) {
acpi_skip_timer_override = 1;
}
/*
* ATI IXP chipsets get double timer interrupts.
* For now just do this for all ATI chipsets.
* FIXME: this needs to be checked for the non ACPI case too.
*/
if (vendor == PCI_VENDOR_ID_ATI)
disable_timer_pin_1 = 1;
return 0;
}
void __init check_acpi_pci(void)
{
int num, slot, func;
/* Assume the machine supports type 1. If not it will
always read ffffffff and should not have any side effect. */
/* Poor man's PCI discovery */
for (num = 0; num < 32; num++) {
for (slot = 0; slot < 32; slot++) {
for (func = 0; func < 8; func++) {
u32 class;
u32 vendor;
class = read_pci_config(num, slot, func,
PCI_CLASS_REVISION);
if (class == 0xffffffff)
break;
if ((class >> 16) != PCI_CLASS_BRIDGE_PCI)
continue;
vendor = read_pci_config(num, slot, func,
PCI_VENDOR_ID);
if (check_bridge(vendor & 0xffff, vendor >> 16))
return;
}
}
}
}