2 files changed, 23 insertions, 7 deletions

diff --git a/arch/powerpc/platforms/powermac/low_i2c.c b/arch/powerpc/platforms/powermac/low_i2c.c
index df2343e1956b..c896ce83d412 100644
--- a/arch/powerpc/platforms/powermac/low_i2c.c
+++ b/arch/powerpc/platforms/powermac/low_i2c.c
@@ -1157,6 +1157,7 @@ EXPORT_SYMBOL_GPL(pmac_i2c_xfer);
 /* some quirks for platform function decoding */
 enum {
 	pmac_i2c_quirk_invmask = 0x00000001u,
+	pmac_i2c_quirk_skip = 0x00000002u,
 };
 
 static void pmac_i2c_devscan(void (*callback)(struct device_node *dev,
@@ -1172,6 +1173,15 @@ static void pmac_i2c_devscan(void (*callback)(struct device_node *dev,
 		/* XXX Study device-tree's & apple drivers are get the quirks
 		 * right !
 		 */
+		/* Workaround: It seems that running the clockspreading
+		 * properties on the eMac will cause lockups during boot.
+		 * The machine seems to work fine without that. So for now,
+		 * let's make sure i2c-hwclock doesn't match about "imic"
+		 * clocks and we'll figure out if we really need to do
+		 * something special about those later.
+		 */
+		{ "i2c-hwclock", "imic5002", pmac_i2c_quirk_skip },
+		{ "i2c-hwclock", "imic5003", pmac_i2c_quirk_skip },
 		{ "i2c-hwclock", NULL, pmac_i2c_quirk_invmask },
 		{ "i2c-cpu-voltage", NULL, 0},
 		{  "temp-monitor", NULL, 0 },
@@ -1198,6 +1208,8 @@ static void pmac_i2c_devscan(void (*callback)(struct device_node *dev,
 				if (p->compatible &&
 				    !device_is_compatible(np, p->compatible))
 					continue;
+				if (p->quirks & pmac_i2c_quirk_skip)
+					break;
 				callback(np, p->quirks);
 				break;
 			}
diff --git a/arch/powerpc/platforms/powermac/pfunc_core.c b/arch/powerpc/platforms/powermac/pfunc_core.c
index 4baa75b1d36f..f08173b0f065 100644
--- a/arch/powerpc/platforms/powermac/pfunc_core.c
+++ b/arch/powerpc/platforms/powermac/pfunc_core.c
@@ -11,6 +11,7 @@
 #include <linux/kernel.h>
 #include <linux/spinlock.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 
 #include <asm/semaphore.h>
 #include <asm/prom.h>
@@ -546,6 +547,7 @@ struct pmf_device {
 
 static LIST_HEAD(pmf_devices);
 static spinlock_t pmf_lock = SPIN_LOCK_UNLOCKED;
+static DEFINE_MUTEX(pmf_irq_mutex);
 
 static void pmf_release_device(struct kref *kref)
 {
@@ -864,15 +866,17 @@ int pmf_register_irq_client(struct device_node *target,
 
 	spin_lock_irqsave(&pmf_lock, flags);
 	func = __pmf_find_function(target, name, PMF_FLAGS_INT_GEN);
-	if (func == NULL) {
-		spin_unlock_irqrestore(&pmf_lock, flags);
+	if (func)
+		func = pmf_get_function(func);
+	spin_unlock_irqrestore(&pmf_lock, flags);
+	if (func == NULL)
 		return -ENODEV;
-	}
+	mutex_lock(&pmf_irq_mutex);
 	if (list_empty(&func->irq_clients))
 		func->dev->handlers->irq_enable(func);
 	list_add(&client->link, &func->irq_clients);
 	client->func = func;
-	spin_unlock_irqrestore(&pmf_lock, flags);
+	mutex_unlock(&pmf_irq_mutex);
 
 	return 0;
 }
@@ -881,16 +885,16 @@ EXPORT_SYMBOL_GPL(pmf_register_irq_client);
 void pmf_unregister_irq_client(struct pmf_irq_client *client)
 {
 	struct pmf_function *func = client->func;
-	unsigned long flags;
 
 	BUG_ON(func == NULL);
 
-	spin_lock_irqsave(&pmf_lock, flags);
+	mutex_lock(&pmf_irq_mutex);
 	client->func = NULL;
 	list_del(&client->link);
 	if (list_empty(&func->irq_clients))
 		func->dev->handlers->irq_disable(func);
-	spin_unlock_irqrestore(&pmf_lock, flags);
+	mutex_unlock(&pmf_irq_mutex);
+	pmf_put_function(func);
 }
 EXPORT_SYMBOL_GPL(pmf_unregister_irq_client);