diff --git a/drivers/mmc/host/sdhci-s3c.c b/drivers/mmc/host/sdhci-s3c.c
index bad0e00..d61eb5a 100644
--- a/drivers/mmc/host/sdhci-s3c.c
+++ b/drivers/mmc/host/sdhci-s3c.c
@@ -126,11 +126,18 @@
 
 	rate = ourhost->clk_rates[src];
 
-	for (shift = 0; shift < 8; ++shift) {
+	for (shift = 0; shift <= 8; ++shift) {
 		if ((rate >> shift) <= wanted)
 			break;
 	}
 
+	if (shift > 8) {
+		dev_dbg(&ourhost->pdev->dev,
+			"clk %d: rate %ld, min rate %lu > wanted %u\n",
+			src, rate, rate / 256, wanted);
+		return UINT_MAX;
+	}
+
 	dev_dbg(&ourhost->pdev->dev, "clk %d: rate %ld, want %d, got %ld\n",
 		src, rate, wanted, rate >> shift);