| From 3defb2476166445982a90c12d33f8947e75476c4 Mon Sep 17 00:00:00 2001 |
| From: =?UTF-8?q?Marek=20Va=C5=A1ut?= <marek.vasut@gmail.com> |
| Date: Wed, 26 May 2010 23:53:09 +0100 |
| Subject: ARM: 6146/1: sa1111: Prevent deadlock in resume path |
| |
| From: =?UTF-8?q?Marek=20Va=C5=A1ut?= <marek.vasut@gmail.com> |
| |
| commit 3defb2476166445982a90c12d33f8947e75476c4 upstream. |
| |
| 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> |
| Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| arch/arm/common/sa1111.c | 9 +++++++-- |
| 1 file changed, 7 insertions(+), 2 deletions(-) |
| |
| --- a/arch/arm/common/sa1111.c |
| +++ b/arch/arm/common/sa1111.c |
| @@ -887,8 +887,6 @@ static int sa1111_resume(struct platform |
| if (!save) |
| return 0; |
| |
| - spin_lock_irqsave(&sachip->lock, flags); |
| - |
| /* |
| * Ensure that the SA1111 is still here. |
| * FIXME: shouldn't do this here. |
| @@ -905,6 +903,13 @@ static int sa1111_resume(struct platform |
| * 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); |
| |
