We cannot process a power_down if the power state is DISABLED. There is
no valid mhi_ctxt in that case, so attepting to process the power_down
will likely result in a null pointer dereference. If the power state is
DISABLED, there is nothing to do anyways, so just bail early.
Signed-off-by: Jeffrey Hugo <jhugo@xxxxxxxxxxxxxx>
---
v3: Move the pm_lock use up
v2: Fix subject and tweak the locking to avoid needless lock/unlock/relock
drivers/bus/mhi/core/pm.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
index 414da4f..ea62549 100644
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -1149,6 +1149,7 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
mhi_deinit_dev_ctxt(mhi_cntrl);
error_dev_ctxt:
+ mhi_cntrl->pm_state = MHI_PM_DISABLE;
mutex_unlock(&mhi_cntrl->pm_mutex);
return ret;
@@ -1160,12 +1161,19 @@ void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful)
enum mhi_pm_state cur_state, transition_state;
struct device *dev = &mhi_cntrl->mhi_dev->dev;
+ mutex_lock(&mhi_cntrl->pm_mutex);
+ write_lock_irq(&mhi_cntrl->pm_lock);
+ cur_state = mhi_cntrl->pm_state;
+ if (cur_state == MHI_PM_DISABLE) {
+ write_unlock_irq(&mhi_cntrl->pm_lock);
+ mutex_unlock(&mhi_cntrl->pm_mutex);
+ return; /* Already powered down */
+ }
+
/* If it's not a graceful shutdown, force MHI to linkdown state */
transition_state = (graceful) ? MHI_PM_SHUTDOWN_PROCESS :
MHI_PM_LD_ERR_FATAL_DETECT;
- mutex_lock(&mhi_cntrl->pm_mutex);
- write_lock_irq(&mhi_cntrl->pm_lock);
cur_state = mhi_tryset_pm_state(mhi_cntrl, transition_state);
if (cur_state != transition_state) {
dev_err(dev, "Failed to move to state: %s from: %s\n",
--
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