From: Jeffrey Hugo <jhugo@codeaurora.org>
To: manivannan.sadhasivam@linaro.org, hemantk@codeaurora.org
Cc: bbhatt@codeaurora.org, linux-arm-msm@vger.kernel.org,
linux-kernel@vger.kernel.org, Jeffrey Hugo <jhugo@codeaurora.org>
Subject: [PATCH v3] bus: mhi: core: Check state before processing power_down
Date: Wed, 10 Mar 2021 13:49:25 -0700 [thread overview]
Message-ID: <1615409365-8165-1-git-send-email-jhugo@codeaurora.org> (raw)
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@codeaurora.org>
---
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",
--
Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.
next reply other threads:[~2021-03-10 20:50 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-10 20:49 Jeffrey Hugo [this message]
2021-03-16 6:16 ` [PATCH v3] bus: mhi: core: Check state before processing power_down Manivannan Sadhasivam
2021-03-16 6:18 ` Manivannan Sadhasivam
2021-05-26 19:03 ` patchwork-bot+linux-arm-msm
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