Re: ACPI: Uninitialized spinlocks & Unable to dump stack

[Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>]

2007-07-31 (火) の 22:48 -0700 に Christoph Lameter さんは書きました:
> With todays git I get (sn2_defconfig w/ spinlock debuggin):

(snip.)

> ACPI: Error parsing MADT - no IOSAPIC entries
> register_intr: No IOSAPIC for GSI 52
> BUG: spinlock bad magic on CPU#0, swapper/0
>  lock: a000000100bf66d0, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 
> 0
> unwind: cannot stack reg state!
> 
> Call Trace:
>  [<a000000100013900>] show_stack+0x40/0xa0

(snip.)

Hi,

I don't know why no IOSAPIC entries was found on your system.
But I think the cause of this stack trace is a bug in the code
path of interrupt registering failure. Here is a patch to fix
this bug. Could you try that?

Thanks,
Kenji Kaneshige

---

Fix wrong access to irq_desc[] in iosapic_register_intr().

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>

---
 arch/ia64/kernel/iosapic.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

Index: linux-2.6.23-rc1/arch/ia64/kernel/iosapic.c
=================================--- linux-2.6.23-rc1.orig/arch/ia64/kernel/iosapic.c
+++ linux-2.6.23-rc1/arch/ia64/kernel/iosapic.c
@@ -794,8 +794,9 @@ iosapic_register_intr (unsigned int gsi,
 	err = register_intr(gsi, irq, IOSAPIC_LOWEST_PRIORITY,
 			    polarity, trigger);
 	if (err < 0) {
+		spin_unlock(&irq_desc[irq].lock);
 		irq = err;
-		goto unlock_all;
+		goto unlock_iosapic_lock;
 	}
 
 	/*
@@ -811,7 +812,7 @@ iosapic_register_intr (unsigned int gsi,
 	       gsi, (trigger = IOSAPIC_EDGE ? "edge" : "level"),
 	       (polarity = IOSAPIC_POL_HIGH ? "high" : "low"),
 	       cpu_logical_id(dest), dest, irq_to_vector(irq));
- unlock_all:
+
 	spin_unlock(&irq_desc[irq].lock);
  unlock_iosapic_lock:
 	spin_unlock_irqrestore(&iosapic_lock, flags);