linux-stable-rt/arch/i386/kernel/acpi/earlyquirk.c

52 lines
1.1 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;
}
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;
}
}
}
}