diff options
author | Andi Kleen <andi@firstfloor.org> | 2009-01-09 20:17:39 (GMT) |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-01-09 20:46:22 (GMT) |
commit | 8659c406ade32f47da2c95889094801921d6330a (patch) | |
tree | b2b263f1adda20a07415db7683f9807a903dc60e /arch/x86/kernel/early-quirks.c | |
parent | 4ce5f24193cef2e26f182ce708e94ba1f5fafc0c (diff) | |
download | linux-8659c406ade32f47da2c95889094801921d6330a.tar.xz |
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>
Diffstat (limited to 'arch/x86/kernel/early-quirks.c')
-rw-r--r-- | arch/x86/kernel/early-quirks.c | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c index 744aa7f..76b8cd9 100644 --- a/arch/x86/kernel/early-quirks.c +++ b/arch/x86/kernel/early-quirks.c @@ -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; + } } |