Merge "mhi: core: Synchronize time sync operation and removal"

drivers/bus/mhi/core/mhi_init.c

@@ -592,7 +592,6 @@ int mhi_init_timesync(struct mhi_controller *mhi_cntrl)
 		return -ENOMEM;
 
 	spin_lock_init(&mhi_tsync->lock);
-	mutex_init(&mhi_tsync->lpm_mutex);
 	INIT_LIST_HEAD(&mhi_tsync->head);
 	init_completion(&mhi_tsync->completion);
 
@@ -1356,6 +1355,7 @@ int of_register_mhi_controller(struct mhi_controller *mhi_cntrl)
 
 	INIT_LIST_HEAD(&mhi_cntrl->transition_list);
 	mutex_init(&mhi_cntrl->pm_mutex);
+	mutex_init(&mhi_cntrl->tsync_mutex);
 	rwlock_init(&mhi_cntrl->pm_lock);
 	spin_lock_init(&mhi_cntrl->transition_lock);
 	spin_lock_init(&mhi_cntrl->wlock);

drivers/bus/mhi/core/mhi_internal.h

@@ -714,7 +714,6 @@ struct mhi_timesync {
 	enum MHI_EV_CCS ccs;
 	struct completion completion;
 	spinlock_t lock; /* list protection */
-	struct mutex lpm_mutex; /* lpm protection */
 	struct list_head head;
 };
 

drivers/bus/mhi/core/mhi_main.c

@@ -782,10 +782,12 @@ static const struct attribute_group mhi_tsync_group = {
 void mhi_destroy_timesync(struct mhi_controller *mhi_cntrl)
 {
 	if (mhi_cntrl->mhi_tsync) {
+		mutex_lock(&mhi_cntrl->tsync_mutex);
 		sysfs_remove_group(&mhi_cntrl->mhi_dev->dev.kobj,
 				   &mhi_tsync_group);
 		kfree(mhi_cntrl->mhi_tsync);
 		mhi_cntrl->mhi_tsync = NULL;
+		mutex_unlock(&mhi_cntrl->tsync_mutex);
 	}
 }
 
@@ -2375,16 +2377,17 @@ int mhi_get_remote_time_sync(struct mhi_device *mhi_dev,
 	struct mhi_timesync *mhi_tsync = mhi_cntrl->mhi_tsync;
 	int ret;
 
+	mutex_lock(&mhi_cntrl->tsync_mutex);
 	/* not all devices support time feature */
-	if (!mhi_tsync)
-		return -EIO;
+	if (!mhi_tsync) {
+		ret = -EIO;
+		goto err_unlock;
+	}
 
 	/* bring to M0 state */
 	ret = __mhi_device_get_sync(mhi_cntrl);
 	if (ret)
-		return ret;
-
-	mutex_lock(&mhi_tsync->lpm_mutex);
+		goto err_unlock;
 
 	read_lock_bh(&mhi_cntrl->pm_lock);
 	if (unlikely(MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state))) {
@@ -2418,8 +2421,8 @@ int mhi_get_remote_time_sync(struct mhi_device *mhi_dev,
 error_invalid_state:
 	mhi_cntrl->wake_put(mhi_cntrl, false);
 	read_unlock_bh(&mhi_cntrl->pm_lock);
-	mutex_unlock(&mhi_tsync->lpm_mutex);
-
+err_unlock:
+	mutex_unlock(&mhi_cntrl->tsync_mutex);
 	return ret;
 }
 EXPORT_SYMBOL(mhi_get_remote_time_sync);
@@ -2447,13 +2450,16 @@ int mhi_get_remote_time(struct mhi_device *mhi_dev,
 	int ret;
 
 	/* not all devices support time feature */
-	if (!mhi_tsync)
-		return -EIO;
+	mutex_lock(&mhi_cntrl->tsync_mutex);
+	if (!mhi_tsync) {
+		ret = -EIO;
+		goto err_unlock;
+	}
 
 	/* tsync db can only be rung in M0 state */
 	ret = __mhi_device_get_sync(mhi_cntrl);
 	if (ret)
-		return ret;
+		goto err_unlock;
 
 	/*
 	 * technically we can use GFP_KERNEL, but wants to avoid
@@ -2512,7 +2518,8 @@ error_no_mem:
 	read_lock_bh(&mhi_cntrl->pm_lock);
 	mhi_cntrl->wake_put(mhi_cntrl, false);
 	read_unlock_bh(&mhi_cntrl->pm_lock);
-
+err_unlock:
+	mutex_unlock(&mhi_cntrl->tsync_mutex);
 	return ret;
 }
 EXPORT_SYMBOL(mhi_get_remote_time);

drivers/bus/mhi/core/mhi_pm.c

@@ -635,6 +635,9 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl,
 	flush_work(&mhi_cntrl->fw_worker);
 	flush_work(&mhi_cntrl->low_priority_worker);
 
+	/* remove support for time sync */
+	mhi_destroy_timesync(mhi_cntrl);
+
 	mutex_lock(&mhi_cntrl->pm_mutex);
 
 	MHI_ASSERT(atomic_read(&mhi_cntrl->dev_wake), "dev_wake != 0");
@@ -669,9 +672,6 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl,
 		er_ctxt->wp = er_ctxt->rbase;
 	}
 
-	/* remove support for time sync */
-	mhi_destroy_timesync(mhi_cntrl);
-
 	if (cur_state == MHI_PM_SYS_ERR_PROCESS) {
 		mhi_ready_state_transition(mhi_cntrl);
 	} else {

include/linux/mhi.h

@@ -303,6 +303,7 @@ struct mhi_controller {
 
 	/* caller should grab pm_mutex for suspend/resume operations */
 	struct mutex pm_mutex;
+	struct mutex tsync_mutex;
 	bool pre_init;
 	rwlock_t pm_lock;
 	u32 pm_state;