1 files changed, 57 insertions, 12 deletions

diff --git a/drivers/bus/mhi/host/pm.c b/drivers/bus/mhi/host/pm.c
index a2f2feef1476..11c0e751f223 100644
--- a/drivers/bus/mhi/host/pm.c
+++ b/drivers/bus/mhi/host/pm.c
@@ -15,6 +15,7 @@
 #include <linux/slab.h>
 #include <linux/wait.h>
 #include "internal.h"
+#include "trace.h"
 
 /*
  * Not all MHI state transitions are synchronous. Transitions like Linkdown,
@@ -36,7 +37,10 @@
  *     M0 <--> M0
  *     M0 -> FW_DL_ERR
  *     M0 -> M3_ENTER -> M3 -> M3_EXIT --> M0
- * L1: SYS_ERR_DETECT -> SYS_ERR_PROCESS --> POR
+ * L1: SYS_ERR_DETECT -> SYS_ERR_PROCESS
+ *     SYS_ERR_PROCESS -> SYS_ERR_FAIL
+ *     SYS_ERR_FAIL -> SYS_ERR_DETECT
+ *     SYS_ERR_PROCESS --> POR
  * L2: SHUTDOWN_PROCESS -> LD_ERR_FATAL_DETECT
  *     SHUTDOWN_PROCESS -> DISABLE
  * L3: LD_ERR_FATAL_DETECT <--> LD_ERR_FATAL_DETECT
@@ -93,7 +97,12 @@ static const struct mhi_pm_transitions dev_state_transitions[] = {
 	},
 	{
 		MHI_PM_SYS_ERR_PROCESS,
-		MHI_PM_POR | MHI_PM_SHUTDOWN_PROCESS |
+		MHI_PM_POR | MHI_PM_SYS_ERR_FAIL | MHI_PM_SHUTDOWN_PROCESS |
+		MHI_PM_LD_ERR_FATAL_DETECT
+	},
+	{
+		MHI_PM_SYS_ERR_FAIL,
+		MHI_PM_SYS_ERR_DETECT | MHI_PM_SHUTDOWN_PROCESS |
 		MHI_PM_LD_ERR_FATAL_DETECT
 	},
 	/* L2 States */
@@ -123,6 +132,7 @@ enum mhi_pm_state __must_check mhi_tryset_pm_state(struct mhi_controller *mhi_cn
 	if (unlikely(!(dev_state_transitions[index].to_states & state)))
 		return cur_state;
 
+	trace_mhi_tryset_pm_state(mhi_cntrl, state);
 	mhi_cntrl->pm_state = state;
 	return mhi_cntrl->pm_state;
 }
@@ -458,7 +468,8 @@ error_mission_mode:
 }
 
 /* Handle shutdown transitions */
-static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl)
+static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl,
+				      bool destroy_device)
 {
 	enum mhi_pm_state cur_state;
 	struct mhi_event *mhi_event;
@@ -520,8 +531,16 @@ skip_mhi_reset:
 	dev_dbg(dev, "Waiting for all pending threads to complete\n");
 	wake_up_all(&mhi_cntrl->state_event);
 
-	dev_dbg(dev, "Reset all active channels and remove MHI devices\n");
-	device_for_each_child(&mhi_cntrl->mhi_dev->dev, NULL, mhi_destroy_device);
+	/*
+	 * Only destroy the 'struct device' for channels if indicated by the
+	 * 'destroy_device' flag. Because, during system suspend or hibernation
+	 * state, there is no need to destroy the 'struct device' as the endpoint
+	 * device would still be physically attached to the machine.
+	 */
+	if (destroy_device) {
+		dev_dbg(dev, "Reset all active channels and remove MHI devices\n");
+		device_for_each_child(&mhi_cntrl->mhi_dev->dev, NULL, mhi_destroy_device);
+	}
 
 	mutex_lock(&mhi_cntrl->pm_mutex);
 
@@ -629,7 +648,13 @@ static void mhi_pm_sys_error_transition(struct mhi_controller *mhi_cntrl)
 					!in_reset, timeout);
 		if (!ret || in_reset) {
 			dev_err(dev, "Device failed to exit MHI Reset state\n");
-			goto exit_sys_error_transition;
+			write_lock_irq(&mhi_cntrl->pm_lock);
+			cur_state = mhi_tryset_pm_state(mhi_cntrl,
+							MHI_PM_SYS_ERR_FAIL);
+			write_unlock_irq(&mhi_cntrl->pm_lock);
+			/* Shutdown may have occurred, otherwise cleanup now */
+			if (cur_state != MHI_PM_SYS_ERR_FAIL)
+				goto exit_sys_error_transition;
 		}
 
 		/*
@@ -758,7 +783,6 @@ void mhi_pm_st_worker(struct work_struct *work)
 	struct mhi_controller *mhi_cntrl = container_of(work,
 							struct mhi_controller,
 							st_worker);
-	struct device *dev = &mhi_cntrl->mhi_dev->dev;
 
 	spin_lock_irq(&mhi_cntrl->transition_lock);
 	list_splice_tail_init(&mhi_cntrl->transition_list, &head);
@@ -766,8 +790,8 @@ void mhi_pm_st_worker(struct work_struct *work)
 
 	list_for_each_entry_safe(itr, tmp, &head, node) {
 		list_del(&itr->node);
-		dev_dbg(dev, "Handling state transition: %s\n",
-			TO_DEV_STATE_TRANS_STR(itr->state));
+
+		trace_mhi_pm_st_transition(mhi_cntrl, itr->state);
 
 		switch (itr->state) {
 		case DEV_ST_TRANSITION_PBL:
@@ -806,7 +830,10 @@ void mhi_pm_st_worker(struct work_struct *work)
 			mhi_pm_sys_error_transition(mhi_cntrl);
 			break;
 		case DEV_ST_TRANSITION_DISABLE:
-			mhi_pm_disable_transition(mhi_cntrl);
+			mhi_pm_disable_transition(mhi_cntrl, false);
+			break;
+		case DEV_ST_TRANSITION_DISABLE_DESTROY_DEVICE:
+			mhi_pm_disable_transition(mhi_cntrl, true);
 			break;
 		default:
 			break;
@@ -1160,7 +1187,8 @@ error_exit:
 }
 EXPORT_SYMBOL_GPL(mhi_async_power_up);
 
-void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful)
+static void __mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful,
+			     bool destroy_device)
 {
 	enum mhi_pm_state cur_state, transition_state;
 	struct device *dev = &mhi_cntrl->mhi_dev->dev;
@@ -1196,15 +1224,32 @@ void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful)
 	write_unlock_irq(&mhi_cntrl->pm_lock);
 	mutex_unlock(&mhi_cntrl->pm_mutex);
 
-	mhi_queue_state_transition(mhi_cntrl, DEV_ST_TRANSITION_DISABLE);
+	if (destroy_device)
+		mhi_queue_state_transition(mhi_cntrl,
+					   DEV_ST_TRANSITION_DISABLE_DESTROY_DEVICE);
+	else
+		mhi_queue_state_transition(mhi_cntrl,
+					   DEV_ST_TRANSITION_DISABLE);
 
 	/* Wait for shutdown to complete */
 	flush_work(&mhi_cntrl->st_worker);
 
 	disable_irq(mhi_cntrl->irq[0]);
 }
+
+void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful)
+{
+	__mhi_power_down(mhi_cntrl, graceful, true);
+}
 EXPORT_SYMBOL_GPL(mhi_power_down);
 
+void mhi_power_down_keep_dev(struct mhi_controller *mhi_cntrl,
+			       bool graceful)
+{
+	__mhi_power_down(mhi_cntrl, graceful, false);
+}
+EXPORT_SYMBOL_GPL(mhi_power_down_keep_dev);
+
 int mhi_sync_power_up(struct mhi_controller *mhi_cntrl)
 {
 	int ret = mhi_async_power_up(mhi_cntrl);