System is a AMD K6-III/450.  This is actually a 2.6.25-rcX issue

that I'm just getting around to reporting.  Sorry about that...
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WARNING: at arch/x86/pci/irq.c:263 pirq_via586_get+0x23/0x42()

Modules linked in: snd_emu10k1(+) snd_rawmidi firmware_class snd_ac97_codec ac97_bus snd_pcm snd_seq_device snd_timer snd_page_alloc snd_util_mem snd_hwdep snd soundcore ipv6 usbmouse usbhid ff_memless uhci_hcd ehci_hcd usbcore binfmt_misc

Pid: 1784, comm: modprobe Not tainted 2.6.25-rc7 #1

 [<c0115b43>] warn_on_slowpath+0x40/0x4f

 [<c012755b>] run_hrtimer_pending+0xac/0xc5

 [<c011cc32>] run_timer_softirq+0x152/0x16b

 [<c0119b8c>] __do_softirq+0x59/0x85

 [<c027246b>] pci_conf1_read+0xac/0xc5

 [<c027334f>] raw_pci_read+0x3f/0x47

 [<c027246b>] pci_conf1_read+0xac/0xc5

 [<c027334f>] raw_pci_read+0x3f/0x47

 [<c0273421>] pci_read+0x1c/0x23

 [<c01f5bce>] pci_bus_read_config_byte+0x37/0x6c

 [<c01f5be8>] pci_bus_read_config_byte+0x51/0x6c

 [<c0272cef>] pirq_via586_get+0x23/0x42

 [<c0272ccc>] pirq_via586_get+0x0/0x42

 [<c0272fa7>] pcibios_lookup_irq+0x1da/0x355

 [<c0273152>] pirq_enable_irq+0x30/0x91

 [<c0273403>] pcibios_enable_device+0x21/0x23

 [<c01f798b>] do_pci_enable_device+0x1f/0x34

 [<c01f79f8>] __pci_enable_device_flags+0x58/0x64

 [<d8c51bb6>] snd_emu10k1_create+0x2f/0x5fb [snd_emu10k1]

 [<d8b87f5b>] snd_card_new+0x1f6/0x24a [snd]

 [<d8c5196e>] snd_card_emu10k1_probe+0xd2/0x2eb [snd_emu10k1]

 [<c01f8d59>] pci_device_probe+0x36/0x57

 [<c022f7d7>] driver_probe_device+0xb7/0x128

 [<c022f8d5>] __driver_attach+0x0/0x75

 [<c022f919>] __driver_attach+0x44/0x75

 [<c022ede5>] bus_for_each_dev+0x38/0x5a

 [<c022f670>] driver_attach+0x11/0x13

 [<c022f8d5>] __driver_attach+0x0/0x75

 [<c022f493>] bus_add_driver+0x8f/0x1ac

 [<c022fae2>] driver_register+0x45/0x99

 [<c01f8f46>] __pci_r...
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[Added Ingo and Thomas to Cc:]
Not necessarily a regression, it's just that the WARN_ON_ONCE didn't

--

Hm, the warnings seem to be a bit broken. They were added in

7d409d6057c7244f8757ce15245f6df27271be0c "x86: add some pirq debugging".
In pirq_via586_{get,set} and pirq_ite_{get,set}, they're missing the

fact that we're using pirq-1 to index the array. So it's spitting out

warnings for valid cases. So Bob's warning can very well be completely

bogus.
In pirq_ali_{get,set} there's probably the same problem, but I can't

really tell for sure, because pirq isn't used to index the array

directly, and the comment above that functions tells me not to guess

anything.
For pirq_vlsi_{get,set} I just wondered why that ">= 9" instead of "> 8"

as it is on the next line, but well, that's just style nit-picking...
Björn

--

Bj

The conditions for the warnings simply ignored the fact that we later actually

use the original value minus 1, so the warning triggered even for valid values.
Signed-off-by: Björn Steinbrink <B.Steinbrink@gmx.de>

---

[Sorry for the resend, I messed up the first one with a Reply-To instead
OK, so I made a guess anyway, the new condition at least makes more

sense to me.
 arch/x86/pci/irq.c |   12 ++++++------

 1 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/arch/x86/pci/irq.c b/arch/x86/pci/irq.c

index a871586..579745c 100644

--- a/arch/x86/pci/irq.c

+++ b/arch/x86/pci/irq.c

@@ -200,7 +200,7 @@ static int pirq_ali_get(struct pci_dev *router, struct pci_dev *dev, int pirq)

 {

 	static const unsigned char irqmap[16] = { 0, 9, 3, 10, 4, 5, 7, 6, 1, 11, 0, 12, 0, 14, 0, 15 };
-	WARN_ON_ONCE(pirq >= 16);

+	WARN_ON_ONCE(pirq > 16);

 	return irqmap[read_config_nybble(router, 0x48, pirq-1)];

 }
@@ -209,7 +209,7 @@ static int pirq_ali_set(struct pci_dev *router, struct pci_dev *dev, int pirq, i

 	static const unsigned char irqmap[16] = { 0, 8, 0, 2, 4, 5, 7, 6, 0, 1, 3, 9, 11, 0, 13, 15 };

 	unsigned int val = irqmap[irq];
-	WARN_ON_ONCE(pirq >= 16);

+	WARN_ON_ONCE(pirq > 16);

 	if (val) {

 		write_config_nybble(router, 0x48, pirq-1, val);

 		return 1;

@@ -260,7 +260,7 @@ static int pirq_via586_get(struct pci_dev *router, struct pci_dev *dev, int pirq

 {

 	static const unsigned int pirqmap[5] = { 3, 2, 5, 1, 1 };
-	WARN_ON_ONCE(pirq >= 5);

+	WARN_ON_ONCE(pirq > 5);

 	return read_config_nybble(router, 0x55, pirqmap[pirq-1]);

 }
@@ -268,7 +268,7 @@ static int pirq_via586_set(struct pci_dev *router, struct pci_dev *dev, int pirq

 {

 	static const unsigned int pirqmap[5] = { 3, 2, 5, 1, 1 };
-	WARN_ON_ONCE(pirq >= 5);

+	WARN_ON_ONCE(pirq > 5);

 	write_config_nybble(router, 0x55, pirqmap[pirq-1], irq);

 	return 1;

 }

@@ -282,7 +282,7 @@ static int pirq_ite_get(struct pci_dev *router, struct pci_dev *dev, int pirq)

 ...
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