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| author | Marek Vašut <marek.vasut@gmail.com> | 2010-05-26 23:53:09 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-05-27 10:36:08 +0100 |
| commit | 3defb2476166445982a90c12d33f8947e75476c4 (patch) | |
| tree | fb5b7b157f741cf2cfcc7436c5d70bd5ae7f53a7 /arch/arm/common/sa1111.c | |
| parent | ba327b1e5296b70745e50bcf0446ae8f82e3d478 (diff) | |
| download | talos-op-linux-3defb2476166445982a90c12d33f8947e75476c4.tar.gz talos-op-linux-3defb2476166445982a90c12d33f8947e75476c4.zip | |
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/sa1111.c')
| -rw-r--r-- | arch/arm/common/sa1111.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/arm/common/sa1111.c b/arch/arm/common/sa1111.c index a52a27c1d9be..6f80665f477e 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); |
