MIPS: lantiq: dma: add small delay after reset

Reading the DMA registers immediately after the reset causes
Data Bus Error. Adding a small delay fixes this issue.
Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/mips/lantiq/xway/dma.c

@@ -11,6 +11,7 @@
 #include <linux/export.h>
 #include <linux/spinlock.h>
 #include <linux/clk.h>
+#include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/of.h>
 
@@ -222,6 +223,8 @@ ltq_dma_init(struct platform_device *pdev)
 	clk_enable(clk);
 	ltq_dma_w32_mask(0, DMA_RESET, LTQ_DMA_CTRL);
 
+	usleep_range(1, 10);
+
 	/* disable all interrupts */
 	ltq_dma_w32(0, LTQ_DMA_IRNEN);