Merge changes I4ac6f9ef,I96bc377c,Ia5fdfb02,I601d24ef into msm-3.0

* changes:
  mmc: core: use non-reentrant workqueue for clock gating
  mmc: core: prevent aggressive clock gating racing with ios updates
  mmc: rename mmc_host_clk_{ungate|gate} to mmc_host_clk_{hold|release}
  Revert "mmc: fix a race between card-detect rescan and clock-gate work instances"
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 008f881..93e1ec6 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -153,7 +153,7 @@
 		if (mrq->done)
 			mrq->done(mrq);
 
-		mmc_host_clk_gate(host);
+		mmc_host_clk_release(host);
 	}
 }
 
@@ -215,7 +215,7 @@
 		host->perf.start = ktime_get();
 #endif
 	}
-	mmc_host_clk_ungate(host);
+	mmc_host_clk_hold(host);
 	led_trigger_event(host->led, LED_FULL);
 	host->ops->request(host, mrq);
 }
@@ -669,15 +669,17 @@
  */
 void mmc_set_chip_select(struct mmc_host *host, int mode)
 {
+	mmc_host_clk_hold(host);
 	host->ios.chip_select = mode;
 	mmc_set_ios(host);
+	mmc_host_clk_release(host);
 }
 
 /*
  * Sets the host clock to the highest possible frequency that
  * is below "hz".
  */
-void mmc_set_clock(struct mmc_host *host, unsigned int hz)
+static void __mmc_set_clock(struct mmc_host *host, unsigned int hz)
 {
 	WARN_ON(hz < host->f_min);
 
@@ -688,6 +690,13 @@
 	mmc_set_ios(host);
 }
 
+void mmc_set_clock(struct mmc_host *host, unsigned int hz)
+{
+	mmc_host_clk_hold(host);
+	__mmc_set_clock(host, hz);
+	mmc_host_clk_release(host);
+}
+
 #ifdef CONFIG_MMC_CLKGATE
 /*
  * This gates the clock by setting it to 0 Hz.
@@ -720,7 +729,7 @@
 	if (host->clk_old) {
 		BUG_ON(host->ios.clock);
 		/* This call will also set host->clk_gated to false */
-		mmc_set_clock(host, host->clk_old);
+		__mmc_set_clock(host, host->clk_old);
 	}
 }
 
@@ -748,8 +757,10 @@
  */
 void mmc_set_bus_mode(struct mmc_host *host, unsigned int mode)
 {
+	mmc_host_clk_hold(host);
 	host->ios.bus_mode = mode;
 	mmc_set_ios(host);
+	mmc_host_clk_release(host);
 }
 
 /*
@@ -757,8 +768,10 @@
  */
 void mmc_set_bus_width(struct mmc_host *host, unsigned int width)
 {
+	mmc_host_clk_hold(host);
 	host->ios.bus_width = width;
 	mmc_set_ios(host);
+	mmc_host_clk_release(host);
 }
 
 /**
@@ -956,8 +969,10 @@
 
 		ocr &= 3 << bit;
 
+		mmc_host_clk_hold(host);
 		host->ios.vdd = bit;
 		mmc_set_ios(host);
+		mmc_host_clk_release(host);
 	} else {
 		pr_warning("%s: host doesn't support card's voltages\n",
 				mmc_hostname(host));
@@ -1004,8 +1019,10 @@
  */
 void mmc_set_timing(struct mmc_host *host, unsigned int timing)
 {
+	mmc_host_clk_hold(host);
 	host->ios.timing = timing;
 	mmc_set_ios(host);
+	mmc_host_clk_release(host);
 }
 
 /*
@@ -1013,8 +1030,10 @@
  */
 void mmc_set_driver_type(struct mmc_host *host, unsigned int drv_type)
 {
+	mmc_host_clk_hold(host);
 	host->ios.drv_type = drv_type;
 	mmc_set_ios(host);
+	mmc_host_clk_release(host);
 }
 
 /*
@@ -1032,6 +1051,8 @@
 {
 	int bit;
 
+	mmc_host_clk_hold(host);
+
 	/* If ocr is set, we use it */
 	if (host->ocr)
 		bit = ffs(host->ocr) - 1;
@@ -1067,10 +1088,14 @@
 	 * time required to reach a stable voltage.
 	 */
 	mmc_delay(10);
+
+	mmc_host_clk_release(host);
 }
 
 static void mmc_power_off(struct mmc_host *host)
 {
+	mmc_host_clk_hold(host);
+
 	host->ios.clock = 0;
 	host->ios.vdd = 0;
 
@@ -1088,6 +1113,8 @@
 	host->ios.bus_width = MMC_BUS_WIDTH_1;
 	host->ios.timing = MMC_TIMING_LEGACY;
 	mmc_set_ios(host);
+
+	mmc_host_clk_release(host);
 }
 
 /*
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
index 3dead90..8703a52 100644
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -94,7 +94,7 @@
 		spin_unlock_irqrestore(&host->clk_lock, flags);
 		return;
 	}
-	mmc_claim_host(host);
+	mutex_lock(&host->clk_gate_mutex);
 	spin_lock_irqsave(&host->clk_lock, flags);
 	if (!host->clk_requests) {
 		spin_unlock_irqrestore(&host->clk_lock, flags);
@@ -104,7 +104,7 @@
 		pr_debug("%s: gated MCI clock\n", mmc_hostname(host));
 	}
 	spin_unlock_irqrestore(&host->clk_lock, flags);
-	mmc_release_host(host);
+	mutex_unlock(&host->clk_gate_mutex);
 }
 
 /*
@@ -119,18 +119,18 @@
 }
 
 /**
- *	mmc_host_clk_ungate - ungate hardware MCI clocks
+ *	mmc_host_clk_hold - ungate hardware MCI clocks
  *	@host: host to ungate.
  *
  *	Makes sure the host ios.clock is restored to a non-zero value
  *	past this call.	Increase clock reference count and ungate clock
  *	if we're the first user.
  */
-void mmc_host_clk_ungate(struct mmc_host *host)
+void mmc_host_clk_hold(struct mmc_host *host)
 {
 	unsigned long flags;
 
-	mmc_claim_host(host);
+	mutex_lock(&host->clk_gate_mutex);
 	spin_lock_irqsave(&host->clk_lock, flags);
 	if (host->clk_gated) {
 		spin_unlock_irqrestore(&host->clk_lock, flags);
@@ -140,7 +140,7 @@
 	}
 	host->clk_requests++;
 	spin_unlock_irqrestore(&host->clk_lock, flags);
-	mmc_release_host(host);
+	mutex_unlock(&host->clk_gate_mutex);
 }
 
 /**
@@ -164,14 +164,14 @@
 }
 
 /**
- *	mmc_host_clk_gate - gate off hardware MCI clocks
+ *	mmc_host_clk_release - gate off hardware MCI clocks
  *	@host: host to gate.
  *
  *	Calls the host driver with ios.clock set to zero as often as possible
  *	in order to gate off hardware MCI clocks. Decrease clock reference
  *	count and schedule disabling of clock.
  */
-void mmc_host_clk_gate(struct mmc_host *host)
+void mmc_host_clk_release(struct mmc_host *host)
 {
 	unsigned long flags;
 
@@ -179,7 +179,7 @@
 	host->clk_requests--;
 	if (mmc_host_may_gate_card(host->card) &&
 	    !host->clk_requests)
-		schedule_work(&host->clk_gate_work);
+		queue_work(system_nrt_wq, &host->clk_gate_work);
 	spin_unlock_irqrestore(&host->clk_lock, flags);
 }
 
@@ -215,6 +215,7 @@
 	host->clk_gated = false;
 	INIT_WORK(&host->clk_gate_work, mmc_host_clk_gate_work);
 	spin_lock_init(&host->clk_lock);
+	mutex_init(&host->clk_gate_mutex);
 }
 
 /**
@@ -230,7 +231,7 @@
 	if (cancel_work_sync(&host->clk_gate_work))
 		mmc_host_clk_gate_delayed(host);
 	if (host->clk_gated)
-		mmc_host_clk_ungate(host);
+		mmc_host_clk_hold(host);
 	/* There should be only one user now */
 	WARN_ON(host->clk_requests > 1);
 }
diff --git a/drivers/mmc/core/host.h b/drivers/mmc/core/host.h
index de199f9..fb8a5cd 100644
--- a/drivers/mmc/core/host.h
+++ b/drivers/mmc/core/host.h
@@ -16,16 +16,16 @@
 void mmc_unregister_host_class(void);
 
 #ifdef CONFIG_MMC_CLKGATE
-void mmc_host_clk_ungate(struct mmc_host *host);
-void mmc_host_clk_gate(struct mmc_host *host);
+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_ungate(struct mmc_host *host)
+static inline void mmc_host_clk_hold(struct mmc_host *host)
 {
 }
 
-static inline void mmc_host_clk_gate(struct mmc_host *host)
+static inline void mmc_host_clk_release(struct mmc_host *host)
 {
 }
 
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index fd62a22..de90088 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -221,6 +221,7 @@
 	struct work_struct	clk_gate_work; /* delayed clock gate */
 	unsigned int		clk_old;	/* old clock value cache */
 	spinlock_t		clk_lock;	/* lock for clk fields */
+	struct mutex		clk_gate_mutex;	/* mutex for clock gating */
 #endif
 
 	/* host specific block data */