1 files changed, 207 insertions, 73 deletions

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 95fedcf56e4a..860378bea557 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -19,7 +19,6 @@
 #include <linux/scatterlist.h>
 #include <linux/log2.h>
 #include <linux/pm_runtime.h>
-#include <linux/pm_wakeup.h>
 #include <linux/suspend.h>
 #include <linux/fault-inject.h>
 #include <linux/random.h>
@@ -56,7 +55,7 @@ static const unsigned freqs[] = { 400000, 300000, 200000, 100000 };
 /*
  * Enabling software CRCs on the data blocks can be a significant (30%)
  * performance cost, and for other reasons may not always be desired.
- * So we allow it it to be disabled.
+ * So we allow it to be disabled.
  */
 bool use_spi_crc = 1;
 module_param(use_spi_crc, bool, 0);
@@ -97,8 +96,8 @@ static void mmc_should_fail_request(struct mmc_host *host,
 	    !should_fail(&host->fail_mmc_request, data->blksz * data->blocks))
 		return;
 
-	data->error = data_errors[prandom_u32() % ARRAY_SIZE(data_errors)];
-	data->bytes_xfered = (prandom_u32() % (data->bytes_xfered >> 9)) << 9;
+	data->error = data_errors[get_random_u32_below(ARRAY_SIZE(data_errors))];
+	data->bytes_xfered = get_random_u32_below(data->bytes_xfered >> 9) << 9;
 }
 
 #else /* CONFIG_FAIL_MMC_REQUEST */
@@ -142,8 +141,7 @@ void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
 	int err = cmd->error;
 
 	/* Flag re-tuning needed on CRC errors */
-	if (cmd->opcode != MMC_SEND_TUNING_BLOCK &&
-	    cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200 &&
+	if (!mmc_op_tuning(cmd->opcode) &&
 	    !host->retune_crc_disable &&
 	    (err == -EILSEQ || (mrq->sbc && mrq->sbc->error == -EILSEQ) ||
 	    (mrq->data && mrq->data->error == -EILSEQ) ||
@@ -337,6 +335,9 @@ int mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
 {
 	int err;
 
+	if (mrq->cmd->has_ext_addr)
+		mmc_send_ext_addr(host, mrq->cmd->ext_addr);
+
 	init_completion(&mrq->cmd_completion);
 
 	mmc_retune_hold(host);
@@ -352,6 +353,9 @@ int mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
 	if (err)
 		return err;
 
+	if (host->uhs2_sd_tran)
+		mmc_uhs2_prepare_cmd(host, mrq);
+
 	led_trigger_event(host->led, LED_FULL);
 	__mmc_start_request(host, mrq);
 
@@ -451,6 +455,9 @@ int mmc_cqe_start_req(struct mmc_host *host, struct mmc_request *mrq)
 	if (err)
 		goto out_err;
 
+	if (host->uhs2_sd_tran)
+		mmc_uhs2_prepare_cmd(host, mrq);
+
 	err = host->cqe_ops->cqe_request(host, mrq);
 	if (err)
 		goto out_err;
@@ -527,7 +534,7 @@ EXPORT_SYMBOL(mmc_cqe_post_req);
  * mmc_cqe_recovery - Recover from CQE errors.
  * @host: MMC host to recover
  *
- * Recovery consists of stopping CQE, stopping eMMC, discarding the queue in
+ * Recovery consists of stopping CQE, stopping eMMC, discarding the queue
  * in eMMC, and discarding the queue in CQE. CQE must call
  * mmc_cqe_request_done() on all requests. An error is returned if the eMMC
  * fails to discard its queue.
@@ -549,21 +556,24 @@ int mmc_cqe_recovery(struct mmc_host *host)
 
 	memset(&cmd, 0, sizeof(cmd));
 	cmd.opcode       = MMC_STOP_TRANSMISSION;
-	cmd.flags        = MMC_RSP_R1B | MMC_CMD_AC;
-	cmd.flags       &= ~MMC_RSP_CRC; /* Ignore CRC */
+	cmd.flags        = MMC_RSP_R1B_NO_CRC | MMC_CMD_AC; /* Ignore CRC */
 	cmd.busy_timeout = MMC_CQE_RECOVERY_TIMEOUT;
-	mmc_wait_for_cmd(host, &cmd, 0);
+	mmc_wait_for_cmd(host, &cmd, MMC_CMD_RETRIES);
+
+	mmc_poll_for_busy(host->card, MMC_CQE_RECOVERY_TIMEOUT, true, MMC_BUSY_IO);
 
 	memset(&cmd, 0, sizeof(cmd));
 	cmd.opcode       = MMC_CMDQ_TASK_MGMT;
 	cmd.arg          = 1; /* Discard entire queue */
-	cmd.flags        = MMC_RSP_R1B | MMC_CMD_AC;
-	cmd.flags       &= ~MMC_RSP_CRC; /* Ignore CRC */
+	cmd.flags        = MMC_RSP_R1B_NO_CRC | MMC_CMD_AC; /* Ignore CRC */
 	cmd.busy_timeout = MMC_CQE_RECOVERY_TIMEOUT;
-	err = mmc_wait_for_cmd(host, &cmd, 0);
+	err = mmc_wait_for_cmd(host, &cmd, MMC_CMD_RETRIES);
 
 	host->cqe_ops->cqe_recovery_finish(host);
 
+	if (err)
+		err = mmc_wait_for_cmd(host, &cmd, MMC_CMD_RETRIES);
+
 	mmc_retune_release(host);
 
 	return err;
@@ -872,7 +882,6 @@ void mmc_put_card(struct mmc_card *card, struct mmc_ctx *ctx)
 	WARN_ON(ctx && host->claimer != ctx);
 
 	mmc_release_host(host);
-	pm_runtime_mark_last_busy(&card->dev);
 	pm_runtime_put_autosuspend(&card->dev);
 }
 EXPORT_SYMBOL(mmc_put_card);
@@ -936,14 +945,17 @@ int mmc_execute_tuning(struct mmc_card *card)
 		opcode = MMC_SEND_TUNING_BLOCK;
 
 	err = host->ops->execute_tuning(host, opcode);
+	if (!err) {
+		mmc_retune_clear(host);
+		mmc_retune_enable(host);
+		return 0;
+	}
 
-	if (err) {
+	/* Only print error when we don't check for card removal */
+	if (!host->detect_change) {
 		pr_err("%s: tuning execution failed: %d\n",
 			mmc_hostname(host), err);
-	} else {
-		host->retune_now = 0;
-		host->need_retune = 0;
-		mmc_retune_enable(host);
+		mmc_debugfs_err_stats_inc(host, MMC_ERR_TUNING);
 	}
 
 	return err;
@@ -1125,13 +1137,19 @@ u32 mmc_select_voltage(struct mmc_host *host, u32 ocr)
 		return 0;
 	}
 
-	if (host->caps2 & MMC_CAP2_FULL_PWR_CYCLE) {
+	if (!mmc_card_uhs2(host) && host->caps2 & MMC_CAP2_FULL_PWR_CYCLE) {
 		bit = ffs(ocr) - 1;
 		ocr &= 3 << bit;
 		mmc_power_cycle(host, ocr);
 	} else {
 		bit = fls(ocr) - 1;
-		ocr &= 3 << bit;
+		/*
+		 * The bit variable represents the highest voltage bit set in
+		 * the OCR register.
+		 * To keep a range of 2 values (e.g. 3.2V/3.3V and 3.3V/3.4V),
+		 * we must shift the mask '3' with (bit - 1).
+		 */
+		ocr &= 3 << (bit - 1);
 		if (bit != host->ios.vdd)
 			dev_warn(mmc_dev(host), "exceeding card's volts\n");
 	}
@@ -1380,6 +1398,29 @@ void mmc_power_cycle(struct mmc_host *host, u32 ocr)
 	mmc_power_up(host, ocr);
 }
 
+/**
+ * mmc_handle_undervoltage - Handle an undervoltage event on the MMC bus
+ * @host: The MMC host that detected the undervoltage condition
+ *
+ * This function is called when an undervoltage event is detected on one of
+ * the MMC regulators.
+ *
+ * Returns: 0 on success or a negative error code on failure.
+ */
+int mmc_handle_undervoltage(struct mmc_host *host)
+{
+	/* Stop the host to prevent races with card removal */
+	__mmc_stop_host(host);
+
+	if (!host->bus_ops || !host->bus_ops->handle_undervoltage)
+		return 0;
+
+	dev_warn(mmc_dev(host), "%s: Undervoltage detected, initiating emergency stop\n",
+		 mmc_hostname(host));
+
+	return host->bus_ops->handle_undervoltage(host);
+}
+
 /*
  * Assign a mmc bus handler to a host. Only one bus handler may control a
  * host at any given time.
@@ -1475,6 +1516,11 @@ void mmc_init_erase(struct mmc_card *card)
 		card->pref_erase = 0;
 }
 
+static bool is_trim_arg(unsigned int arg)
+{
+	return (arg & MMC_TRIM_OR_DISCARD_ARGS) && arg != MMC_DISCARD_ARG;
+}
+
 static unsigned int mmc_mmc_erase_timeout(struct mmc_card *card,
 				          unsigned int arg, unsigned int qty)
 {
@@ -1580,8 +1626,8 @@ static unsigned int mmc_erase_timeout(struct mmc_card *card,
 		return mmc_mmc_erase_timeout(card, arg, qty);
 }
 
-static int mmc_do_erase(struct mmc_card *card, unsigned int from,
-			unsigned int to, unsigned int arg)
+static int mmc_do_erase(struct mmc_card *card, sector_t from,
+			sector_t to, unsigned int arg)
 {
 	struct mmc_command cmd = {};
 	unsigned int qty = 0, busy_timeout = 0;
@@ -1612,8 +1658,8 @@ static int mmc_do_erase(struct mmc_card *card, unsigned int from,
 	else if (mmc_card_sd(card))
 		qty += to - from + 1;
 	else
-		qty += ((to / card->erase_size) -
-			(from / card->erase_size)) + 1;
+		qty += (mmc_sector_div(to, card->erase_size) -
+			mmc_sector_div(from, card->erase_size)) + 1;
 
 	if (!mmc_card_blockaddr(card)) {
 		from <<= 9;
@@ -1626,6 +1672,12 @@ static int mmc_do_erase(struct mmc_card *card, unsigned int from,
 		cmd.opcode = MMC_ERASE_GROUP_START;
 	cmd.arg = from;
 	cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
+
+	if (mmc_card_ult_capacity(card)) {
+		cmd.ext_addr = from >> 32;
+		cmd.has_ext_addr = true;
+	}
+
 	err = mmc_wait_for_cmd(card->host, &cmd, 0);
 	if (err) {
 		pr_err("mmc_erase: group start error %d, "
@@ -1641,6 +1693,12 @@ static int mmc_do_erase(struct mmc_card *card, unsigned int from,
 		cmd.opcode = MMC_ERASE_GROUP_END;
 	cmd.arg = to;
 	cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
+
+	if (mmc_card_ult_capacity(card)) {
+		cmd.ext_addr = to >> 32;
+		cmd.has_ext_addr = true;
+	}
+
 	err = mmc_wait_for_cmd(card->host, &cmd, 0);
 	if (err) {
 		pr_err("mmc_erase: group end error %d, status %#x\n",
@@ -1682,18 +1740,19 @@ out:
 }
 
 static unsigned int mmc_align_erase_size(struct mmc_card *card,
-					 unsigned int *from,
-					 unsigned int *to,
+					 sector_t *from,
+					 sector_t *to,
 					 unsigned int nr)
 {
-	unsigned int from_new = *from, nr_new = nr, rem;
+	sector_t from_new = *from;
+	unsigned int nr_new = nr, rem;
 
 	/*
 	 * When the 'card->erase_size' is power of 2, we can use round_up/down()
 	 * to align the erase size efficiently.
 	 */
 	if (is_power_of_2(card->erase_size)) {
-		unsigned int temp = from_new;
+		sector_t temp = from_new;
 
 		from_new = round_up(temp, card->erase_size);
 		rem = from_new - temp;
@@ -1705,7 +1764,7 @@ static unsigned int mmc_align_erase_size(struct mmc_card *card,
 
 		nr_new = round_down(nr_new, card->erase_size);
 	} else {
-		rem = from_new % card->erase_size;
+		rem = mmc_sector_mod(from_new, card->erase_size);
 		if (rem) {
 			rem = card->erase_size - rem;
 			from_new += rem;
@@ -1738,10 +1797,12 @@ static unsigned int mmc_align_erase_size(struct mmc_card *card,
  *
  * Caller must claim host before calling this function.
  */
-int mmc_erase(struct mmc_card *card, unsigned int from, unsigned int nr,
+int mmc_erase(struct mmc_card *card, sector_t from, unsigned int nr,
 	      unsigned int arg)
 {
-	unsigned int rem, to = from + nr;
+	unsigned int rem;
+	sector_t to = from + nr;
+
 	int err;
 
 	if (!(card->csd.cmdclass & CCC_ERASE))
@@ -1757,12 +1818,12 @@ int mmc_erase(struct mmc_card *card, unsigned int from, unsigned int nr,
 	    !(card->ext_csd.sec_feature_support & EXT_CSD_SEC_ER_EN))
 		return -EOPNOTSUPP;
 
-	if (mmc_card_mmc(card) && (arg & MMC_TRIM_ARGS) &&
+	if (mmc_card_mmc(card) && is_trim_arg(arg) &&
 	    !(card->ext_csd.sec_feature_support & EXT_CSD_SEC_GB_CL_EN))
 		return -EOPNOTSUPP;
 
 	if (arg == MMC_SECURE_ERASE_ARG) {
-		if (from % card->erase_size || nr % card->erase_size)
+		if (mmc_sector_mod(from, card->erase_size) || nr % card->erase_size)
 			return -EINVAL;
 	}
 
@@ -1786,8 +1847,8 @@ int mmc_erase(struct mmc_card *card, unsigned int from, unsigned int nr,
 	 * and call mmc_do_erase() twice if necessary. This special case is
 	 * identified by the card->eg_boundary flag.
 	 */
-	rem = card->erase_size - (from % card->erase_size);
-	if ((arg & MMC_TRIM_ARGS) && (card->eg_boundary) && (nr > rem)) {
+	rem = card->erase_size - mmc_sector_mod(from, card->erase_size);
+	if ((arg & MMC_TRIM_OR_DISCARD_ARGS) && card->eg_boundary && nr > rem) {
 		err = mmc_do_erase(card, from, from + rem - 1, arg);
 		from += rem;
 		if ((err) || (to <= from))
@@ -1798,59 +1859,60 @@ int mmc_erase(struct mmc_card *card, unsigned int from, unsigned int nr,
 }
 EXPORT_SYMBOL(mmc_erase);
 
-int mmc_can_erase(struct mmc_card *card)
+bool mmc_card_can_erase(struct mmc_card *card)
 {
-	if (card->csd.cmdclass & CCC_ERASE && card->erase_size)
-		return 1;
-	return 0;
+	return (card->csd.cmdclass & CCC_ERASE && card->erase_size);
 }
-EXPORT_SYMBOL(mmc_can_erase);
+EXPORT_SYMBOL(mmc_card_can_erase);
 
-int mmc_can_trim(struct mmc_card *card)
+bool mmc_card_can_trim(struct mmc_card *card)
 {
-	if ((card->ext_csd.sec_feature_support & EXT_CSD_SEC_GB_CL_EN) &&
-	    (!(card->quirks & MMC_QUIRK_TRIM_BROKEN)))
-		return 1;
-	return 0;
+	return ((card->ext_csd.sec_feature_support & EXT_CSD_SEC_GB_CL_EN) &&
+		(!(card->quirks & MMC_QUIRK_TRIM_BROKEN)));
 }
-EXPORT_SYMBOL(mmc_can_trim);
+EXPORT_SYMBOL(mmc_card_can_trim);
 
-int mmc_can_discard(struct mmc_card *card)
+bool mmc_card_can_discard(struct mmc_card *card)
 {
 	/*
 	 * As there's no way to detect the discard support bit at v4.5
 	 * use the s/w feature support filed.
 	 */
-	if (card->ext_csd.feature_support & MMC_DISCARD_FEATURE)
-		return 1;
-	return 0;
+	return (card->ext_csd.feature_support & MMC_DISCARD_FEATURE);
 }
-EXPORT_SYMBOL(mmc_can_discard);
+EXPORT_SYMBOL(mmc_card_can_discard);
 
-int mmc_can_sanitize(struct mmc_card *card)
+bool mmc_card_can_sanitize(struct mmc_card *card)
 {
-	if (!mmc_can_trim(card) && !mmc_can_erase(card))
-		return 0;
+	if (!mmc_card_can_trim(card) && !mmc_card_can_erase(card))
+		return false;
 	if (card->ext_csd.sec_feature_support & EXT_CSD_SEC_SANITIZE)
-		return 1;
-	return 0;
+		return true;
+	return false;
 }
 
-int mmc_can_secure_erase_trim(struct mmc_card *card)
+bool mmc_card_can_secure_erase_trim(struct mmc_card *card)
 {
-	if ((card->ext_csd.sec_feature_support & EXT_CSD_SEC_ER_EN) &&
-	    !(card->quirks & MMC_QUIRK_SEC_ERASE_TRIM_BROKEN))
-		return 1;
-	return 0;
+	return ((card->ext_csd.sec_feature_support & EXT_CSD_SEC_ER_EN) &&
+		!(card->quirks & MMC_QUIRK_SEC_ERASE_TRIM_BROKEN));
 }
-EXPORT_SYMBOL(mmc_can_secure_erase_trim);
+EXPORT_SYMBOL(mmc_card_can_secure_erase_trim);
 
-int mmc_erase_group_aligned(struct mmc_card *card, unsigned int from,
+bool mmc_card_can_cmd23(struct mmc_card *card)
+{
+	return ((mmc_card_mmc(card) &&
+		 card->csd.mmca_vsn >= CSD_SPEC_VER_3) ||
+		(mmc_card_sd(card) && !mmc_card_ult_capacity(card) &&
+		 card->scr.cmds & SD_SCR_CMD23_SUPPORT));
+}
+EXPORT_SYMBOL(mmc_card_can_cmd23);
+
+int mmc_erase_group_aligned(struct mmc_card *card, sector_t from,
 			    unsigned int nr)
 {
 	if (!card->erase_size)
 		return 0;
-	if (from % card->erase_size || nr % card->erase_size)
+	if (mmc_sector_mod(from, card->erase_size) || nr % card->erase_size)
 		return 0;
 	return 1;
 }
@@ -1948,7 +2010,7 @@ unsigned int mmc_calc_max_discard(struct mmc_card *card)
 		return card->pref_erase;
 
 	max_discard = mmc_do_calc_max_discard(card, MMC_ERASE_ARG);
-	if (mmc_can_trim(card)) {
+	if (mmc_card_can_trim(card)) {
 		max_trim = mmc_do_calc_max_discard(card, MMC_TRIM_ARG);
 		if (max_trim < max_discard || max_discard == 0)
 			max_discard = max_trim;
@@ -1987,14 +2049,14 @@ static void mmc_hw_reset_for_init(struct mmc_host *host)
 {
 	mmc_pwrseq_reset(host);
 
-	if (!(host->caps & MMC_CAP_HW_RESET) || !host->ops->hw_reset)
+	if (!(host->caps & MMC_CAP_HW_RESET) || !host->ops->card_hw_reset)
 		return;
-	host->ops->hw_reset(host);
+	host->ops->card_hw_reset(host);
 }
 
 /**
  * mmc_hw_reset - reset the card in hardware
- * @host: MMC host to which the card is attached
+ * @card: card to be reset
  *
  * Hard reset the card. This function is only for upper layers, like the
  * block layer or card drivers. You cannot use it in host drivers (struct
@@ -2002,8 +2064,9 @@ static void mmc_hw_reset_for_init(struct mmc_host *host)
  *
  * Return: 0 on success, -errno on failure
  */
-int mmc_hw_reset(struct mmc_host *host)
+int mmc_hw_reset(struct mmc_card *card)
 {
+	struct mmc_host *host = card->host;
 	int ret;
 
 	ret = host->bus_ops->hw_reset(host);
@@ -2015,8 +2078,9 @@ int mmc_hw_reset(struct mmc_host *host)
 }
 EXPORT_SYMBOL(mmc_hw_reset);
 
-int mmc_sw_reset(struct mmc_host *host)
+int mmc_sw_reset(struct mmc_card *card)
 {
+	struct mmc_host *host = card->host;
 	int ret;
 
 	if (!host->bus_ops->sw_reset)
@@ -2149,6 +2213,41 @@ int mmc_detect_card_removed(struct mmc_host *host)
 }
 EXPORT_SYMBOL(mmc_detect_card_removed);
 
+int mmc_card_alternative_gpt_sector(struct mmc_card *card, sector_t *gpt_sector)
+{
+	unsigned int boot_sectors_num;
+
+	if ((!(card->host->caps2 & MMC_CAP2_ALT_GPT_TEGRA)))
+		return -EOPNOTSUPP;
+
+	/* filter out unrelated cards */
+	if (card->ext_csd.rev < 3 ||
+	    !mmc_card_mmc(card) ||
+	    !mmc_card_is_blockaddr(card) ||
+	     mmc_card_is_removable(card->host))
+		return -ENOENT;
+
+	/*
+	 * eMMC storage has two special boot partitions in addition to the
+	 * main one.  NVIDIA's bootloader linearizes eMMC boot0->boot1->main
+	 * accesses, this means that the partition table addresses are shifted
+	 * by the size of boot partitions.  In accordance with the eMMC
+	 * specification, the boot partition size is calculated as follows:
+	 *
+	 *	boot partition size = 128K byte x BOOT_SIZE_MULT
+	 *
+	 * Calculate number of sectors occupied by the both boot partitions.
+	 */
+	boot_sectors_num = card->ext_csd.raw_boot_mult * SZ_128K /
+			   SZ_512 * MMC_NUM_BOOT_PARTITION;
+
+	/* Defined by NVIDIA and used by Android devices. */
+	*gpt_sector = card->ext_csd.sectors - boot_sectors_num - 1;
+
+	return 0;
+}
+EXPORT_SYMBOL(mmc_card_alternative_gpt_sector);
+
 void mmc_rescan(struct work_struct *work)
 {
 	struct mmc_host *host =
@@ -2194,6 +2293,18 @@ void mmc_rescan(struct work_struct *work)
 		goto out;
 	}
 
+	/*
+	 * Ideally we should favor initialization of legacy SD cards and defer
+	 * UHS-II enumeration. However, it seems like cards doesn't reliably
+	 * announce their support for UHS-II in the response to the ACMD41,
+	 * while initializing the legacy SD interface. Therefore, let's start
+	 * with UHS-II for now.
+	 */
+	if (!mmc_attach_sd_uhs2(host)) {
+		mmc_release_host(host);
+		goto out;
+	}
+
 	for (i = 0; i < ARRAY_SIZE(freqs); i++) {
 		unsigned int freq = freqs[i];
 		if (freq > host->f_max) {
@@ -2206,6 +2317,17 @@ void mmc_rescan(struct work_struct *work)
 		if (freqs[i] <= host->f_min)
 			break;
 	}
+
+	/* A non-removable card should have been detected by now. */
+	if (!mmc_card_is_removable(host) && !host->bus_ops)
+		pr_info("%s: Failed to initialize a non-removable card",
+			mmc_hostname(host));
+
+	/*
+	 * Ignore the command timeout errors observed during
+	 * the card init as those are excepted.
+	 */
+	host->err_stats[MMC_ERR_CMD_TIMEOUT] = 0;
 	mmc_release_host(host);
 
  out:
@@ -2215,10 +2337,13 @@ void mmc_rescan(struct work_struct *work)
 
 void mmc_start_host(struct mmc_host *host)
 {
+	bool power_up = !(host->caps2 &
+			 (MMC_CAP2_NO_PRESCAN_POWERUP | MMC_CAP2_SD_UHS2));
+
 	host->f_init = max(min(freqs[0], host->f_max), host->f_min);
 	host->rescan_disable = 0;
 
-	if (!(host->caps2 & MMC_CAP2_NO_PRESCAN_POWERUP)) {
+	if (power_up) {
 		mmc_claim_host(host);
 		mmc_power_up(host, host->ocr_avail);
 		mmc_release_host(host);
@@ -2228,8 +2353,11 @@ void mmc_start_host(struct mmc_host *host)
 	_mmc_detect_change(host, 0, false);
 }
 
-void mmc_stop_host(struct mmc_host *host)
+void __mmc_stop_host(struct mmc_host *host)
 {
+	if (host->rescan_disable)
+		return;
+
 	if (host->slot.cd_irq >= 0) {
 		mmc_gpio_set_cd_wake(host, false);
 		disable_irq(host->slot.cd_irq);
@@ -2237,6 +2365,11 @@ void mmc_stop_host(struct mmc_host *host)
 
 	host->rescan_disable = 1;
 	cancel_delayed_work_sync(&host->detect);
+}
+
+void mmc_stop_host(struct mmc_host *host)
+{
+	__mmc_stop_host(host);
 
 	/* clear pm flags now and let card drivers set them as needed */
 	host->pm_flags = 0;
@@ -2291,4 +2424,5 @@ static void __exit mmc_exit(void)
 subsys_initcall(mmc_init);
 module_exit(mmc_exit);
 
+MODULE_DESCRIPTION("MMC core driver");
 MODULE_LICENSE("GPL");