mmc: core: Do not poll for busy with status cmd for all switch cmds

Some switch operations like poweroff notify, shall according to the
spec not be followed by any other new commands. For these cases and
when the host does'nt support MMC_CAP_WAIT_WHILE_BUSY, we must not
send status commands to poll for busy detection. Instead wait for
the stated timeout from the EXT_CSD before completing the request.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/core/core.c

@@ -301,7 +301,7 @@ void mmc_start_bkops(struct mmc_card *card, bool from_exception)
 	}
 
 	err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
-			EXT_CSD_BKOPS_START, 1, timeout, use_busy_signal);
+			EXT_CSD_BKOPS_START, 1, timeout, use_busy_signal, true);
 	if (err) {
 		pr_warn("%s: Error %d starting bkops\n",
 			mmc_hostname(card->host), err);

drivers/mmc/core/mmc.c

@@ -1404,9 +1404,9 @@ static int mmc_poweroff_notify(struct mmc_card *card, unsigned int notify_type)
 	if (notify_type == EXT_CSD_POWER_OFF_LONG)
 		timeout = card->ext_csd.power_off_longtime;
 
-	err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
-			 EXT_CSD_POWER_OFF_NOTIFICATION,
-			 notify_type, timeout);
+	err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+			EXT_CSD_POWER_OFF_NOTIFICATION,
+			notify_type, timeout, true, false);
 	if (err)
 		pr_err("%s: Power Off Notification timed out, %u\n",
 		       mmc_hostname(card->host), timeout);

drivers/mmc/core/mmc_ops.c

@@ -404,11 +404,12 @@ int mmc_spi_set_crc(struct mmc_host *host, int use_crc)
  *	@timeout_ms: timeout (ms) for operation performed by register write,
  *                   timeout of zero implies maximum possible timeout
  *	@use_busy_signal: use the busy signal as response type
+ *	@send_status: send status cmd to poll for busy
  *
  *	Modifies the EXT_CSD register for selected card.
  */
 int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
-	       unsigned int timeout_ms, bool use_busy_signal)
+		unsigned int timeout_ms, bool use_busy_signal, bool send_status)
 {
 	int err;
 	struct mmc_command cmd = {0};
@@ -454,14 +455,26 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
 
 	timeout = jiffies + msecs_to_jiffies(MMC_OPS_TIMEOUT_MS);
 	do {
-		err = __mmc_send_status(card, &status, ignore_crc);
-		if (err)
-			return err;
+		if (send_status) {
+			err = __mmc_send_status(card, &status, ignore_crc);
+			if (err)
+				return err;
+		}
 		if (card->host->caps & MMC_CAP_WAIT_WHILE_BUSY)
 			break;
 		if (mmc_host_is_spi(card->host))
 			break;
 
+		/*
+		 * We are not allowed to issue a status command and the host
+		 * does'nt support MMC_CAP_WAIT_WHILE_BUSY, then we can only
+		 * rely on waiting for the stated timeout to be sufficient.
+		 */
+		if (!send_status) {
+			mmc_delay(timeout_ms);
+			return 0;
+		}
+
 		/* Timeout if the device never leaves the program state. */
 		if (time_after(jiffies, timeout)) {
 			pr_err("%s: Card stuck in programming state! %s\n",
@@ -488,7 +501,7 @@ EXPORT_SYMBOL_GPL(__mmc_switch);
 int mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
 		unsigned int timeout_ms)
 {
-	return __mmc_switch(card, set, index, value, timeout_ms, true);
+	return __mmc_switch(card, set, index, value, timeout_ms, true, true);
 }
 EXPORT_SYMBOL_GPL(mmc_switch);
 

include/linux/mmc/core.h

@@ -151,7 +151,8 @@ extern int mmc_app_cmd(struct mmc_host *, struct mmc_card *);
 extern int mmc_wait_for_app_cmd(struct mmc_host *, struct mmc_card *,
 	struct mmc_command *, int);
 extern void mmc_start_bkops(struct mmc_card *card, bool from_exception);
-extern int __mmc_switch(struct mmc_card *, u8, u8, u8, unsigned int, bool);
+extern int __mmc_switch(struct mmc_card *, u8, u8, u8, unsigned int, bool,
+			bool);
 extern int mmc_switch(struct mmc_card *, u8, u8, u8, unsigned int);
 extern int mmc_send_ext_csd(struct mmc_card *card, u8 *ext_csd);