arm: mach-davinci: check irq2ctlr() result

If irq2ctlr() fails return IRQ_NONE.
Also as it can fail make 'ctlr' signed.

The semantic patch that finds this problem (many false-positive results):
(http://coccinelle.lip6.fr/)

// <smpl>
@ r1 @
identifier f;
@@
int f(...) { ... }

@@
identifier r1.f;
type T;
unsigned T x;
@@

*x = f(...)
 ...
*x > 0

Signed-off-by: Kulikov Vasiliy <segooon@gmail.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/arch/arm/mach-davinci/dma.c b/arch/arm/mach-davinci/dma.c
index 2ede598b77d..6b9669869c4 100644
--- a/arch/arm/mach-davinci/dma.c
+++ b/arch/arm/mach-davinci/dma.c
@@ -354,10 +354,12 @@ static int irq2ctlr(int irq)
 static irqreturn_t dma_irq_handler(int irq, void *data)
 {
         int i;
-        unsigned ctlr;
+        int ctlr;
         unsigned int cnt = 0;
 
         ctlr = irq2ctlr(irq);
+        if (ctlr < 0)
+                return IRQ_NONE;
 
         dev_dbg(data, "dma_irq_handler\n");
 
@@ -408,10 +410,12 @@ static irqreturn_t dma_irq_handler(int irq, void *data)
 static irqreturn_t dma_ccerr_handler(int irq, void *data)
 {
         int i;
-        unsigned ctlr;
+        int ctlr;
         unsigned int cnt = 0;
 
         ctlr = irq2ctlr(irq);
+        if (ctlr < 0)
+                return IRQ_NONE;
 
         dev_dbg(data, "dma_ccerr_handler\n");