Messages in this thread Patch in this message | | | From | Jeffrey Hugo <> | Subject | [PATCH v3] bus: mhi: core: Check state before processing power_down | Date | Wed, 10 Mar 2021 13:49:25 -0700 |
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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.
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