net: stmmac: Use readl_poll_timeout

The dwmac_dma_reset function use an open coded of readl_poll_timeout().
Replace the open coded handling with the proper function.
Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Acked-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/dwmac_lib.c

@@ -17,6 +17,7 @@
 *******************************************************************************/
 
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include "common.h"
 #include "dwmac_dma.h"
 
@@ -25,19 +26,16 @@
 int dwmac_dma_reset(void __iomem *ioaddr)
 {
 	u32 value = readl(ioaddr + DMA_BUS_MODE);
-	int limit;
+	int err;
 
 	/* DMA SW reset */
 	value |= DMA_BUS_MODE_SFT_RESET;
 	writel(value, ioaddr + DMA_BUS_MODE);
-	limit = 10;
-	while (limit--) {
-		if (!(readl(ioaddr + DMA_BUS_MODE) & DMA_BUS_MODE_SFT_RESET))
-			break;
-		mdelay(10);
-	}
 
-	if (limit < 0)
+	err = readl_poll_timeout(ioaddr + DMA_BUS_MODE, value,
+				 !(value & DMA_BUS_MODE_SFT_RESET),
+				 100000, 10000);
+	if (err)
 		return -EBUSY;
 
 	return 0;