Blackfin: add dma_disable_irq_nosync() API for irq handlers

Some IRQ handlers need to disable a DMA channel without waiting.

Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/arch/blackfin/include/asm/dma.h b/arch/blackfin/include/asm/dma.h
index bd2e622..2c09b1d 100644
--- a/arch/blackfin/include/asm/dma.h
+++ b/arch/blackfin/include/asm/dma.h
@@ -262,6 +262,10 @@
 {
 	disable_irq(dma_ch[channel].irq);
 }
+static inline void dma_disable_irq_nosync(unsigned int channel)
+{
+	disable_irq_nosync(dma_ch[channel].irq);
+}
 static inline void dma_enable_irq(unsigned int channel)
 {
 	enable_irq(dma_ch[channel].irq);