[PATCH] fix deadlock in drivers/pci/msi.c

The lock validator caught another one: drivers/pci/msi.c is accessing
&irq_desc[i].lock with interrupts enabled (!).

The fix is to disable interrupts properly.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 202b7507a357..8e1ba0b7a8e4 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -416,7 +416,9 @@ static void attach_msi_entry(struct msi_desc *entry, int vector)
 
 static void irq_handler_init(int cap_id, int pos, int mask)
 {
-        spin_lock(&irq_desc[pos].lock);
+        unsigned long flags;
+
+        spin_lock_irqsave(&irq_desc[pos].lock, flags);
         if (cap_id == PCI_CAP_ID_MSIX)
                 irq_desc[pos].handler = &msix_irq_type;
         else {
@@ -425,7 +427,7 @@ static void irq_handler_init(int cap_id, int pos, int mask)
                 else
                         irq_desc[pos].handler = &msi_irq_w_maskbit_type;
         }
-        spin_unlock(&irq_desc[pos].lock);
+        spin_unlock_irqrestore(&irq_desc[pos].lock, flags);
 }
 
 static void enable_msi_mode(struct pci_dev *dev, int pos, int type)