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>

diff --git a/arch/blackfin/kernel/bfin_dma_5xx.c b/arch/blackfin/kernel/bfin_dma_5xx.c
index 639dcee..924c002 100644 (file)
--- 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);