From: Marek VaĊĦut Date: Wed, 26 May 2010 22:53:09 +0000 (+0100) Subject: ARM: 6146/1: sa1111: Prevent deadlock in resume path X-Git-Tag: firefly_0821_release~9833^2~1528^2~5 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=3defb2476166445982a90c12d33f8947e75476c4;p=firefly-linux-kernel-4.4.55.git 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 2) The function didn't unlock the spinlock in case the chip didn't report correct ID. Original idea for this part: Julia Lawall Signed-off-by: Marek Vasut Cc: Signed-off-by: Russell King --- 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);