diff mbox series

[10/14] bus: mhi: core: Handle disable transitions in state worker

Message ID 20200521152540.17335-11-mani@kernel.org (mailing list archive)
State Accepted
Commit 3c1bd0047124f506294520341cfe03e19ea773e3
Headers show
Series MHI patches for v5.8 | expand

Commit Message

Manivannan Sadhasivam May 21, 2020, 3:25 p.m. UTC 
From: Hemant Kumar <hemantk@codeaurora.org>

Mission mode transition is handled by state worker thread but
power off is not. There is a possibility while mission mode
transition is in progress which calls MHI client driver probe,
power off is issued by MHI controller. This results into client
driver probe and remove running in parallel and causes use after
free situation. By queuing disable transition work when mission
mode is in progress prevents the race condition.

Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>
Reviewed-by: Jeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/init.c     |  1 +
 drivers/bus/mhi/core/internal.h |  1 +
 drivers/bus/mhi/core/pm.c       | 11 ++++++++++-
 3 files changed, 12 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index 3a853c5d2103..12207cc438aa 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -35,6 +35,7 @@  const char * const dev_state_tran_str[DEV_ST_TRANSITION_MAX] = {
 	[DEV_ST_TRANSITION_SBL] = "SBL",
 	[DEV_ST_TRANSITION_MISSION_MODE] = "MISSION_MODE",
 	[DEV_ST_TRANSITION_SYS_ERR] = "SYS_ERR",
+	[DEV_ST_TRANSITION_DISABLE] = "DISABLE",
 };
 
 const char * const mhi_state_str[MHI_STATE_MAX] = {
diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h
index f01283b8a451..b1f640b75a94 100644
--- a/drivers/bus/mhi/core/internal.h
+++ b/drivers/bus/mhi/core/internal.h
@@ -387,6 +387,7 @@  enum dev_st_transition {
 	DEV_ST_TRANSITION_SBL,
 	DEV_ST_TRANSITION_MISSION_MODE,
 	DEV_ST_TRANSITION_SYS_ERR,
+	DEV_ST_TRANSITION_DISABLE,
 	DEV_ST_TRANSITION_MAX,
 };
 
diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
index 743b3207c390..a5d9973059c8 100644
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -657,6 +657,10 @@  void mhi_pm_st_worker(struct work_struct *work)
 			mhi_pm_disable_transition
 				(mhi_cntrl, MHI_PM_SYS_ERR_PROCESS);
 			break;
+		case DEV_ST_TRANSITION_DISABLE:
+			mhi_pm_disable_transition
+				(mhi_cntrl, MHI_PM_SHUTDOWN_PROCESS);
+			break;
 		default:
 			break;
 		}
@@ -868,7 +872,12 @@  void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful)
 				to_mhi_pm_state_str(MHI_PM_LD_ERR_FATAL_DETECT),
 				to_mhi_pm_state_str(mhi_cntrl->pm_state));
 	}
-	mhi_pm_disable_transition(mhi_cntrl, MHI_PM_SHUTDOWN_PROCESS);
+
+	mhi_queue_state_transition(mhi_cntrl, DEV_ST_TRANSITION_DISABLE);
+
+	/* Wait for shutdown to complete */
+	flush_work(&mhi_cntrl->st_worker);
+
 	mhi_deinit_free_irq(mhi_cntrl);
 
 	if (!mhi_cntrl->pre_init) {