[PATCH 1/2] arch/arm/plat-mxc: Add local_irq_restore in error handling code

[PATCH 1/2] arch/arm/plat-mxc: Add local_irq_restore in error handling code

[Julia Lawall]

From: Julia Lawall <julia@diku.dk>

There is a call to local_irq_restore in the normal exit case, so it would
seem that there should be one on an error return as well.

The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
expression l;
expression E,E1,E2;
@@

local_irq_save(l);
... when != local_irq_restore(l)
    when != spin_unlock_irqrestore(E,l)
    when any
    when strict
(
if (...) { ... when != local_irq_restore(l)
               when != spin_unlock_irqrestore(E1,l)
+   local_irq_restore(l);
    return ...;
}
|
if (...)
+   {local_irq_restore(l);
    return ...;
+   }
|
spin_unlock_irqrestore(E2,l);
|
local_irq_restore(l);
)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>

---
 arch/arm/plat-mxc/dma-mx1-mx2.c |    1 +
 1 file changed, 1 insertion(+)

diff -u -p a/arch/arm/plat-mxc/dma-mx1-mx2.c b/arch/arm/plat-mxc/dma-mx1-mx2.c
--- a/arch/arm/plat-mxc/dma-mx1-mx2.c
+++ b/arch/arm/plat-mxc/dma-mx1-mx2.c
@@ -698,6 +698,7 @@ int imx_dma_request(int channel, const c
 	if (ret) {
 		printk(KERN_CRIT "Can't register IRQ %d for DMA channel %d\n",
 				MXC_INT_DMACH0 + channel, channel);
+		local_irq_restore(flags);
 		return ret;
 	}
 	init_timer(&imxdma->watchdog);

Re: [PATCH 1/2] arch/arm/plat-mxc: Add local_irq_restore in error handling code

[Sascha Hauer]

Hi,

On Sun, Dec 21, 2008 at 09:54:23PM +0100, Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>
> 
> There is a call to local_irq_restore in the normal exit case, so it would
> seem that there should be one on an error return as well.

Yes, that's correct. Thanks for the patch. A fix for this is already
scheduled upstream though.

Sascha

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Re: [PATCH 1/2] arch/arm/plat-mxc: Add local_irq_restore in error handling code

[Russell King - ARM Linux]

On Sun, Dec 21, 2008 at 09:54:23PM +0100, Julia Lawall wrote:
> There is a call to local_irq_restore in the normal exit case, so it would
> seem that there should be one on an error return as well.

Please check what's queued up for the next merge; a similar change is
already merged as part of a larger patch.  (which is more correct
since it calls local_irq_restore before the printk.)