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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>
This commit is contained in:
Marek Vašut 2010-05-26 23:53:09 +01:00 committed by Russell King
parent ba327b1e52
commit 3defb24761
1 changed files with 7 additions and 2 deletions
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9
arch/arm/common/sa1111.c
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@ -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);