Blackfin: reject NULL callback in set_dma_callback()

It makes no sense to call this function with a NULL callback.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 10 insertions, 11 deletions

diff --git a/arch/blackfin/kernel/bfin_dma_5xx.c b/arch/blackfin/kernel/bfin_dma_5xx.c
index 639dcee5611c..924c00286bab 100644
--- a/arch/blackfin/kernel/bfin_dma_5xx.c
+++ b/arch/blackfin/kernel/bfin_dma_5xx.c
@@ -138,21 +138,20 @@ EXPORT_SYMBOL(request_dma);
 
 int set_dma_callback(unsigned int channel, irq_handler_t callback, void *data)
 {
-        BUG_ON(channel >= MAX_DMA_CHANNELS ||
+        int ret;
+        unsigned int irq;
+
+        BUG_ON(channel >= MAX_DMA_CHANNELS || !callback ||
                         !atomic_read(&dma_ch[channel].chan_status));
 
-        if (callback != NULL) {
-                int ret;
-                unsigned int irq = channel2irq(channel);
+        irq = channel2irq(channel);
+        ret = request_irq(irq, callback, 0, dma_ch[channel].device_id, data);
+        if (ret)
+                return ret;
 
-                ret = request_irq(irq, callback, IRQF_DISABLED,
-                        dma_ch[channel].device_id, data);
-                if (ret)
-                        return ret;
+        dma_ch[channel].irq = irq;
+        dma_ch[channel].data = data;
 
-                dma_ch[channel].irq = irq;
-                dma_ch[channel].data = data;
-        }
         return 0;
 }
 EXPORT_SYMBOL(set_dma_callback);