Re: [PATCH] mhi_bus: core: Check state before processing power_down

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 2021-02-16 01:38 PM, Jeffrey Hugo wrote:
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>
---
 drivers/bus/mhi/core/pm.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
index 56ba3ab..dc69074 100644
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -1144,6 +1144,7 @@ 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;
@@ -1155,6 +1156,12 @@ 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);
+	cur_state = mhi_cntrl->pm_state;
+	mutex_unlock(&mhi_cntrl->pm_mutex);
+	if (cur_state == MHI_PM_DISABLE)
Let's unlock the mutex here and not at the top. We acquire it below anyway.
+		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;

Thanks,
Bhaumik
---
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project



[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [Linux for Sparc]     [IETF Annouce]     [Security]     [Bugtraq]     [Linux MIPS]     [ECOS]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux