mmc: Handle switch error status bit in MMC card status

MMC switch command for unsupported feature (e.g. bus width) sets a switch
error bit in card status. This bit should be checked, and, if it's set,
no access with new controller settings should be performed.

Acked-by: Pantelis Antoniou <panto@antoniou-consulting.com>
Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>

drivers/mmc/mmc.c

@@ -150,6 +150,8 @@ int mmc_send_status(struct mmc *mmc, int timeout)
 #endif
 		return TIMEOUT;
 	}
+	if (cmd.response[0] & MMC_STATUS_SWITCH_ERROR)
+		return SWITCH_ERR;
 
 	return 0;
 }
@@ -501,7 +503,7 @@ static int mmc_change_freq(struct mmc *mmc)
 	err = mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_HS_TIMING, 1);
 
 	if (err)
-		return err;
+		return err == SWITCH_ERR ? 0 : err;
 
 	/* Now check to see that it worked */
 	err = mmc_send_ext_csd(mmc, ext_csd);

include/mmc.h

@@ -54,6 +54,7 @@
 #define COMM_ERR		-18 /* Communications Error */
 #define TIMEOUT			-19
 #define IN_PROGRESS		-20 /* operation is in progress */
+#define SWITCH_ERR		-21 /* Card reports failure to switch mode */
 
 #define MMC_CMD_GO_IDLE_STATE		0
 #define MMC_CMD_SEND_OP_COND		1
@@ -109,6 +110,7 @@
 #define SECURE_ERASE		0x80000000
 
 #define MMC_STATUS_MASK		(~0x0206BF7F)
+#define MMC_STATUS_SWITCH_ERROR	(1 << 7)
 #define MMC_STATUS_RDY_FOR_DATA (1 << 8)
 #define MMC_STATUS_CURR_STATE	(0xf << 9)
 #define MMC_STATUS_ERROR	(1 << 19)