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Commit | Line | Data |
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2cb7cef9 BS |
1 | From: Andi Kleen <ak@linux.intel.com> |
2 | Subject: Only scan the root bus in early PCI quirks. | |
3 | References: bnc#57886 | |
4 | Patch-Mainline: submitted for .29 | |
5 | ||
6 | We found a situation on Linus' machine that the Nvidia timer | |
7 | quirk hit on a Intel chipset system. The problem is that the | |
8 | system has a fancy Nvidia card with an own PCI bridge, and | |
9 | the early-quirks code looking for any NVidia bridge triggered | |
10 | on it incorrectly. This didn't lead a boot failure by luck, | |
11 | but the timer routing code selecting the wrong timer first and | |
12 | some ugly messages. It might lead to real problems on | |
13 | other systems. | |
14 | ||
15 | I checked all the devices which are currently checked for | |
16 | by early_quirks and it turns out they are all located in | |
17 | the root bus zero. | |
18 | ||
19 | So change the early-quirks loop to only scan bus 0. This | |
20 | incidently also saves quite some unnecessary scanning work, | |
21 | because early_quirks doesn't go through all the non root | |
22 | busses. | |
23 | ||
24 | The graphics card is not on bus 0, so it is not matched | |
25 | anymore. | |
26 | ||
27 | Signed-off-by: Andi Kleen <ak@linux.intel.com> | |
28 | Signed-off-by: Thomas Renninger <trenn@suse.de> | |
29 | ||
30 | Index: linux-2.6.28-rc5-test/arch/x86/kernel/early-quirks.c | |
31 | =================================================================== | |
32 | --- linux-2.6.28-rc5-test.orig/arch/x86/kernel/early-quirks.c | |
33 | +++ linux-2.6.28-rc5-test/arch/x86/kernel/early-quirks.c | |
34 | @@ -200,6 +200,12 @@ struct chipset { | |
35 | void (*f)(int num, int slot, int func); | |
36 | }; | |
37 | ||
38 | +/* | |
39 | + * Only works for devices on the root bus. If you add any devices | |
40 | + * not on bus 0 readd another loop level in early_quirks(). But | |
41 | + * be careful because at least the Nvidia quirk here relies on | |
42 | + * only matching on bus 0. | |
43 | + */ | |
44 | static struct chipset early_qrk[] __initdata = { | |
45 | { PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID, | |
46 | PCI_CLASS_BRIDGE_PCI, PCI_ANY_ID, QFLAG_APPLY_ONCE, nvidia_bugs }, | |
47 | @@ -266,17 +272,17 @@ static int __init check_dev_quirk(int nu | |
48 | ||
49 | void __init early_quirks(void) | |
50 | { | |
51 | - int num, slot, func; | |
52 | + int slot, func; | |
53 | ||
54 | if (!early_pci_allowed()) | |
55 | return; | |
56 | ||
57 | /* Poor man's PCI discovery */ | |
58 | - for (num = 0; num < 32; num++) | |
59 | - for (slot = 0; slot < 32; slot++) | |
60 | - for (func = 0; func < 8; func++) { | |
61 | - /* Only probe function 0 on single fn devices */ | |
62 | - if (check_dev_quirk(num, slot, func)) | |
63 | - break; | |
64 | - } | |
65 | + /* Only scan the root bus */ | |
66 | + for (slot = 0; slot < 32; slot++) | |
67 | + for (func = 0; func < 8; func++) { | |
68 | + /* Only probe function 0 on single fn devices */ | |
69 | + if (check_dev_quirk(0, slot, func)) | |
70 | + break; | |
71 | + } | |
72 | } |