mmc: sh_mobile_sdhi: check return value when changing clk

And return the old clock rate if something went wrong.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sh_mobile_sdhi.c

@@ -166,7 +166,7 @@ static unsigned int sh_mobile_sdhi_clk_update(struct tmio_mmc_host *host,
 {
 	struct sh_mobile_sdhi *priv = host_to_priv(host);
 	unsigned int freq, diff, best_freq = 0, diff_min = ~0;
-	int i;
+	int i, ret;
 
 	/* tested only on RCar Gen2+ currently; may work for others */
 	if (!(host->pdata->flags & TMIO_MMC_MIN_RCAR2))
@@ -195,9 +195,9 @@ static unsigned int sh_mobile_sdhi_clk_update(struct tmio_mmc_host *host,
 		}
 	}
 
-	clk_set_rate(priv->clk, best_freq);
+	ret = clk_set_rate(priv->clk, best_freq);
 
-	return best_freq;
+	return ret == 0 ? best_freq : clk_get_rate(priv->clk);
 }
 
 static void sh_mobile_sdhi_clk_disable(struct tmio_mmc_host *host)