diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index 89b674bb..3262740 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -658,7 +658,7 @@
 }
 
 
-int mmc_send_ext_csd(struct mmc *mmc, char *ext_csd)
+int mmc_send_ext_csd(struct mmc *mmc, u8 *ext_csd)
 {
 	struct mmc_cmd cmd;
 	struct mmc_data data;
@@ -669,7 +669,7 @@
 	cmd.resp_type = MMC_RSP_R1;
 	cmd.cmdarg = 0;
 
-	data.dest = ext_csd;
+	data.dest = (char *)ext_csd;
 	data.blocks = 1;
 	data.blocksize = 512;
 	data.flags = MMC_DATA_READ;
@@ -704,7 +704,7 @@
 
 int mmc_change_freq(struct mmc *mmc)
 {
-	ALLOC_CACHE_ALIGN_BUFFER(char, ext_csd, 512);
+	ALLOC_CACHE_ALIGN_BUFFER(u8, ext_csd, 512);
 	char cardtype;
 	int err;
 
@@ -963,8 +963,8 @@
 	uint mult, freq;
 	u64 cmult, csize, capacity;
 	struct mmc_cmd cmd;
-	ALLOC_CACHE_ALIGN_BUFFER(char, ext_csd, 512);
-	ALLOC_CACHE_ALIGN_BUFFER(char, test_csd, 512);
+	ALLOC_CACHE_ALIGN_BUFFER(u8, ext_csd, 512);
+	ALLOC_CACHE_ALIGN_BUFFER(u8, test_csd, 512);
 	int timeout = 1000;
 
 #ifdef CONFIG_MMC_SPI_CRC_ON