mmc: check status after MMC SWITCH command

According to the standard, the SWITCH command should be followed by a
SEND_STATUS command to check for errors.

Signed-off-by: Adrian Hunter <[e-mail]>
Acked-by: Matt Fleming <[e-mail]>
Cc: Ian Molton <[e-mail]>
Cc: "Roberto A. Foglietta" <[e-mail]>
Cc: Jarkko Lavinen <[e-mail]>
Cc: Denis Karpov <[e-mail]>
Cc: Pierre Ossman <[e-mail]>
Cc: Philip Langdale <[e-mail]>
Cc: "Madhusudhan" <[e-mail]>
Cc: <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/mmc/core/mmc.c

···
 		(host->caps & MMC_CAP_MMC_HIGHSPEED)) {
 		err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
 			EXT_CSD_HS_TIMING, 1);
-		if (err)
+		if (err && err != -EBADMSG)
 			goto free_card;
 
-		mmc_card_set_highspeed(card);
-
-		mmc_set_timing(card->host, MMC_TIMING_MMC_HS);
+		if (err) {
+			printk(KERN_WARNING "%s: switch to highspeed failed\n",
+			       mmc_hostname(card->host));
+			err = 0;
+		} else {
+			mmc_card_set_highspeed(card);
+			mmc_set_timing(card->host, MMC_TIMING_MMC_HS);
+		}
 	}
 
 	/*
···
 		err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
 				 EXT_CSD_BUS_WIDTH, ext_csd_bit);
 
-		if (err)
+		if (err && err != -EBADMSG)
 			goto free_card;
 
-		mmc_set_bus_width(card->host, bus_width);
+		if (err) {
+			printk(KERN_WARNING "%s: switch to bus width %d "
+			       "failed\n", mmc_hostname(card->host),
+			       1 << bus_width);
+			err = 0;
+		} else {
+			mmc_set_bus_width(card->host, bus_width);
+		}
 	}
 
 	if (!oldcard)

drivers/mmc/core/mmc_ops.c

···
 {
 	int err;
 	struct mmc_command cmd;
+	u32 status;
 
 	BUG_ON(!card);
 	BUG_ON(!card->host);
···
 	err = mmc_wait_for_cmd(card->host, &cmd, MMC_CMD_RETRIES);
 	if (err)
 		return err;
+
+	/* Must check status to be sure of no errors */
+	do {
+		err = mmc_send_status(card, &status);
+		if (err)
+			return err;
+		if (card->host->caps & MMC_CAP_WAIT_WHILE_BUSY)
+			break;
+		if (mmc_host_is_spi(card->host))
+			break;
+	} while (R1_CURRENT_STATE(status) == 7);
+
+	if (mmc_host_is_spi(card->host)) {
+		if (status & R1_SPI_ILLEGAL_COMMAND)
+			return -EBADMSG;
+	} else {
+		if (status & 0xFDFFA000)
+			printk(KERN_WARNING "%s: unexpected status %#x after "
+			       "switch", mmc_hostname(card->host), status);
+		if (status & R1_SWITCH_ERROR)
+			return -EBADMSG;
+	}
 
 	return 0;
 }

include/linux/mmc/mmc.h

···
 #define R1_STATUS(x)            (x & 0xFFFFE000)
 #define R1_CURRENT_STATE(x)	((x & 0x00001E00) >> 9)	/* sx, b (4 bits) */
 #define R1_READY_FOR_DATA	(1 << 8)	/* sx, a */
+#define R1_SWITCH_ERROR		(1 << 7)	/* sx, c */
 #define R1_APP_CMD		(1 << 5)	/* sr, c */
 
 /*