bus: mhi: core: Move to an error state on mission mode failure

If the host receives a mission mode event and by the time it can get
to processing it, the register accesses fail implying a connectivity
error, MHI should move to an error state. This helps avoid longer wait
times from a synchronous power up perspective and accurately reflects
the MHI execution environment and power management states.
Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

drivers/bus/mhi/core/pm.c

@@ -383,10 +383,14 @@ static int mhi_pm_mission_mode_transition(struct mhi_controller *mhi_cntrl)
 	write_lock_irq(&mhi_cntrl->pm_lock);
 	if (MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state))
 		mhi_cntrl->ee = mhi_get_exec_env(mhi_cntrl);
-	write_unlock_irq(&mhi_cntrl->pm_lock);
 
-	if (!MHI_IN_MISSION_MODE(mhi_cntrl->ee))
+	if (!MHI_IN_MISSION_MODE(mhi_cntrl->ee)) {
+		mhi_cntrl->pm_state = MHI_PM_LD_ERR_FATAL_DETECT;
+		write_unlock_irq(&mhi_cntrl->pm_lock);
+		wake_up_all(&mhi_cntrl->state_event);
 		return -EIO;
+	}
+	write_unlock_irq(&mhi_cntrl->pm_lock);
 
 	wake_up_all(&mhi_cntrl->state_event);