mmc: core: Ensure clocks are always enabled before host interaction

Ensure clocks are always enabled before any interaction with the
host controller driver. This makes sure that there is no race
between host execution and the core layer turning off clocks
in different context with clock gating framework.

CRs-Fixed: 324380
Change-Id: Id3dc2074ed81bf758649bc61ce918500a95e9bae
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 1116ca8..2c7c0a5 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -412,7 +412,9 @@
 		int err;
 
 		host->en_dis_recurs = 1;
+		mmc_host_clk_hold(host);
 		err = host->ops->enable(host);
+		mmc_host_clk_release(host);
 		host->en_dis_recurs = 0;
 
 		if (err) {
@@ -432,7 +434,9 @@
 		int err;
 
 		host->en_dis_recurs = 1;
+		mmc_host_clk_hold(host);
 		err = host->ops->disable(host, lazy);
+		mmc_host_clk_release(host);
 		host->en_dis_recurs = 0;
 
 		if (err < 0) {
@@ -1003,8 +1007,11 @@
 
 	host->ios.signal_voltage = signal_voltage;
 
-	if (host->ops->start_signal_voltage_switch)
+	if (host->ops->start_signal_voltage_switch) {
+		mmc_host_clk_hold(host);
 		err = host->ops->start_signal_voltage_switch(host, &host->ios);
+		mmc_host_clk_release(host);
+	}
 
 	return err;
 }
diff --git a/drivers/mmc/core/host.h b/drivers/mmc/core/host.h
index fb8a5cd..08a7852 100644
--- a/drivers/mmc/core/host.h
+++ b/drivers/mmc/core/host.h
@@ -14,27 +14,6 @@
 
 int mmc_register_host_class(void);
 void mmc_unregister_host_class(void);
-
-#ifdef CONFIG_MMC_CLKGATE
-void mmc_host_clk_hold(struct mmc_host *host);
-void mmc_host_clk_release(struct mmc_host *host);
-unsigned int mmc_host_clk_rate(struct mmc_host *host);
-
-#else
-static inline void mmc_host_clk_hold(struct mmc_host *host)
-{
-}
-
-static inline void mmc_host_clk_release(struct mmc_host *host)
-{
-}
-
-static inline unsigned int mmc_host_clk_rate(struct mmc_host *host)
-{
-	return host->ios.clock;
-}
-#endif
-
 void mmc_host_deeper_disable(struct work_struct *work);
 
 #endif
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 8175d9b..71518f6 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -649,8 +649,11 @@
 		goto out;
 
 	/* SPI mode doesn't define CMD19 */
-	if (!mmc_host_is_spi(card->host) && card->host->ops->execute_tuning)
+	if (!mmc_host_is_spi(card->host) && card->host->ops->execute_tuning) {
+		mmc_host_clk_hold(card->host);
 		err = card->host->ops->execute_tuning(card->host);
+		mmc_host_clk_release(card->host);
+	}
 
 out:
 	kfree(status);
@@ -860,8 +863,11 @@
 	if (!reinit) {
 		int ro = -1;
 
-		if (host->ops->get_ro)
+		if (host->ops->get_ro) {
+			mmc_host_clk_hold(host);
 			ro = host->ops->get_ro(host);
+			mmc_host_clk_release(host);
+		}
 
 		if (ro < 0) {
 			printk(KERN_WARNING "%s: host does not "
@@ -979,8 +985,11 @@
 		 * Since initialization is now complete, enable preset
 		 * value registers for UHS-I cards.
 		 */
-		if (host->ops->enable_preset_value)
+		if (host->ops->enable_preset_value) {
+			mmc_host_clk_hold(host);
 			host->ops->enable_preset_value(host, true);
+			mmc_host_clk_release(host);
+		}
 	} else {
 		/*
 		 * Attempt to change to high-speed (if supported)
@@ -1195,8 +1204,11 @@
 		return err;
 
 	/* Disable preset value enable if already set since last time */
-	if (host->ops->enable_preset_value)
+	if (host->ops->enable_preset_value) {
+		mmc_host_clk_hold(host);
 		host->ops->enable_preset_value(host, false);
+		mmc_host_clk_release(host);
+	}
 
 	err = mmc_send_app_op_cond(host, 0, &ocr);
 	if (err)
diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 2024824..3237742 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -397,8 +397,11 @@
 	/*
 	 * Call the optional HC's init_card function to handle quirks.
 	 */
-	if (host->ops->init_card)
+	if (host->ops->init_card) {
+		mmc_host_clk_hold(host);
 		host->ops->init_card(host, card);
+		mmc_host_clk_release(host);
+	}
 
 	/*
 	 * For native busses:  set card RCA and quit open drain mode.
diff --git a/drivers/mmc/core/sdio_irq.c b/drivers/mmc/core/sdio_irq.c
index 03ead02..8b250c12 100644
--- a/drivers/mmc/core/sdio_irq.c
+++ b/drivers/mmc/core/sdio_irq.c
@@ -145,15 +145,21 @@
 		}
 
 		set_current_state(TASK_INTERRUPTIBLE);
-		if (host->caps & MMC_CAP_SDIO_IRQ)
+		if (host->caps & MMC_CAP_SDIO_IRQ) {
+			mmc_host_clk_hold(host);
 			host->ops->enable_sdio_irq(host, 1);
+			mmc_host_clk_release(host);
+		}
 		if (!kthread_should_stop())
 			schedule_timeout(period);
 		set_current_state(TASK_RUNNING);
 	} while (!kthread_should_stop());
 
-	if (host->caps & MMC_CAP_SDIO_IRQ)
+	if (host->caps & MMC_CAP_SDIO_IRQ) {
+		mmc_host_clk_hold(host);
 		host->ops->enable_sdio_irq(host, 0);
+		mmc_host_clk_release(host);
+	}
 
 	pr_debug("%s: IRQ thread exiting with code %d\n",
 		 mmc_hostname(host), ret);