Commit 9e40641f authored by Jeffrey Hugo's avatar Jeffrey Hugo Committed by Manivannan Sadhasivam
Browse files

bus: mhi: core: Check state before processing power_down 



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: default avatarJeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: default avatarManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1615409365-8165-1-git-send-email-jhugo@codeaurora.org


Signed-off-by: default avatarManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
parent 68731852

drivers/bus/mhi/core/pm.c

+10 −2
Original line number Diff line number Diff line
@@ -1134,6 +1134,7 @@ 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;
@@ -1145,12 +1146,19 @@ 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",