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authorMarek VaĊĦut <marek.vasut@gmail.com>2010-05-26 23:53:09 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2010-05-27 10:36:08 +0100
commit3defb2476166445982a90c12d33f8947e75476c4 (patch)
treefb5b7b157f741cf2cfcc7436c5d70bd5ae7f53a7 /arch/arm/common
parentba327b1e5296b70745e50bcf0446ae8f82e3d478 (diff)
ARM: 6146/1: sa1111: Prevent deadlock in resume path
This patch reorganises the sa1111_resume() function in a manner the spinlock happens after calling the sa1111_wake(). This fixes two bugs: 1) This function called sa1111_wake() which tried to claim the same spinlock the sa1111_resume() already claimed. This would result in certain deadlock. Original idea for this part: Russell King <rmk+kernel@arm.linux.org.uk> 2) The function didn't unlock the spinlock in case the chip didn't report correct ID. Original idea for this part: Julia Lawall <julia@diku.dk> Signed-off-by: Marek Vasut <marek.vasut@gmail.com> Cc: <stable@kernel.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/common')
-rw-r--r--arch/arm/common/sa1111.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/arm/common/sa1111.c b/arch/arm/common/sa1111.c
index a52a27c1d9b..6f80665f477 100644
--- a/arch/arm/common/sa1111.c
+++ b/arch/arm/common/sa1111.c
@@ -951,8 +951,6 @@ static int sa1111_resume(struct platform_device *dev)
if (!save)
return 0;
- spin_lock_irqsave(&sachip->lock, flags);
-
/*
* Ensure that the SA1111 is still here.
* FIXME: shouldn't do this here.
@@ -969,6 +967,13 @@ static int sa1111_resume(struct platform_device *dev)
* First of all, wake up the chip.
*/
sa1111_wake(sachip);
+
+ /*
+ * Only lock for write ops. Also, sa1111_wake must be called with
+ * released spinlock!
+ */
+ spin_lock_irqsave(&sachip->lock, flags);
+
sa1111_writel(0, sachip->base + SA1111_INTC + SA1111_INTEN0);
sa1111_writel(0, sachip->base + SA1111_INTC + SA1111_INTEN1);