x86: only scan the root bus in early PCI quirks
We found a situation on Linus' machine that the Nvidia timer quirk hit on a Intel chipset system. The problem is that the system has a fancy Nvidia card with an own PCI bridge, and the early-quirks code looking for any NVidia bridge triggered on it incorrectly. This didn't lead a boot failure by luck, but the timer routing code selecting the wrong timer first and some ugly messages. It might lead to real problems on other systems. I checked all the devices which are currently checked for by early_quirks and it turns out they are all located in the root bus zero. So change the early-quirks loop to only scan bus 0. This incidently also saves quite some unnecessary scanning work, because early_quirks doesn't go through all the non root busses. The graphics card is not on bus 0, so it is not matched anymore. Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
4ce5f24193
commit
8659c406ad
|
@ -201,6 +201,12 @@ struct chipset {
|
|||
void (*f)(int num, int slot, int func);
|
||||
};
|
||||
|
||||
/*
|
||||
* Only works for devices on the root bus. If you add any devices
|
||||
* not on bus 0 readd another loop level in early_quirks(). But
|
||||
* be careful because at least the Nvidia quirk here relies on
|
||||
* only matching on bus 0.
|
||||
*/
|
||||
static struct chipset early_qrk[] __initdata = {
|
||||
{ PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID,
|
||||
PCI_CLASS_BRIDGE_PCI, PCI_ANY_ID, QFLAG_APPLY_ONCE, nvidia_bugs },
|
||||
|
@ -267,17 +273,17 @@ static int __init check_dev_quirk(int num, int slot, int func)
|
|||
|
||||
void __init early_quirks(void)
|
||||
{
|
||||
int num, slot, func;
|
||||
int slot, func;
|
||||
|
||||
if (!early_pci_allowed())
|
||||
return;
|
||||
|
||||
/* Poor man's PCI discovery */
|
||||
for (num = 0; num < 32; num++)
|
||||
for (slot = 0; slot < 32; slot++)
|
||||
for (func = 0; func < 8; func++) {
|
||||
/* Only probe function 0 on single fn devices */
|
||||
if (check_dev_quirk(num, slot, func))
|
||||
break;
|
||||
}
|
||||
/* Only scan the root bus */
|
||||
for (slot = 0; slot < 32; slot++)
|
||||
for (func = 0; func < 8; func++) {
|
||||
/* Only probe function 0 on single fn devices */
|
||||
if (check_dev_quirk(0, slot, func))
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
|
Loading…
Reference in New Issue