diff -Nur a/drivers/mmc/sunxi_mmc.c b/drivers/mmc/sunxi_mmc.c
--- a/drivers/mmc/sunxi_mmc.c	2016-02-25 10:30:30.000000000 +0800
+++ b//drivers/mmc/sunxi_mmc.c	2016-02-25 10:46:07.723851155 +0800

@@ -269,6 +269,6 @@	
	unsigned i;
	unsigned *buff = (unsigned int *)(reading ? data->dest : data->src);
	unsigned byte_cnt = data->blocksize * data->blocks;
-	unsigned timeout_msecs = byte_cnt >> 8;
+	unsigned timeout_msecs = byte_cnt >> 6;
	if (timeout_msecs < 2000)
		timeout_msecs = 2000;