mxc : BUG in imx_dma_request

On MX2 platforms imx_dma_request() calls request_irq() which may sleep
with interrupts disabled.
Signed-off-by: NMartin Fuzzey <mfuzzey@gmail.com>
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>

arch/arm/plat-mxc/dma-mx1-mx2.c

@@ -693,12 +693,15 @@ int imx_dma_request(int channel, const char *name)
 		local_irq_restore(flags);
 		return -EBUSY;
 	}
+	memset(imxdma, 0, sizeof(imxdma));
+	imxdma->name = name;
+	local_irq_restore(flags); /* request_irq() can block */
 
 #ifdef CONFIG_ARCH_MX2
 	ret = request_irq(MXC_INT_DMACH0 + channel, dma_irq_handler, 0, "DMA",
 			NULL);
 	if (ret) {
-		local_irq_restore(flags);
+		imxdma->name = NULL;
 		printk(KERN_CRIT "Can't register IRQ %d for DMA channel %d\n",
 				MXC_INT_DMACH0 + channel, channel);
 		return ret;
@@ -708,13 +711,6 @@ int imx_dma_request(int channel, const char *name)
 	imxdma->watchdog.data = channel;
 #endif
 
-	imxdma->name = name;
-	imxdma->irq_handler = NULL;
-	imxdma->err_handler = NULL;
-	imxdma->data = NULL;
-	imxdma->sg = NULL;
-
-	local_irq_restore(flags);
 	return ret;
 }
 EXPORT_SYMBOL(imx_dma_request);