diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 7721de942c6..c471cdb1a0b 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -1061,7 +1061,15 @@ static int __devinit mmci_probe(struct amba_device *dev,
 	}
 
 	mmc->ops = &mmci_ops;
-	mmc->f_min = (host->mclk + 511) / 512;
+	/*
+	 * The ARM and ST versions of the block have slightly different
+	 * clock divider equations which means that the minimum divider
+	 * differs too.
+	 */
+	if (variant->st_clkdiv)
+		mmc->f_min = DIV_ROUND_UP(host->mclk, 257);
+	else
+		mmc->f_min = DIV_ROUND_UP(host->mclk, 512);
 	/*
 	 * If the platform data supplies a maximum operating
 	 * frequency, this takes precedence. Else, we fall back