Commit 3defb247 authored May 26, 2010 by Marek Vašut Committed by Russell King May 27, 2010

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>

parent ba327b1e

arch/arm/common/sa1111.c

+7 −2

Original line number	Diff line number	Diff line
		@@ -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);