Messages in this thread | | | Date | Tue, 16 Feb 2021 14:58:04 -0800 | From | Bhaumik Bhatt <> | Subject | Re: [PATCH] mhi_bus: core: Check state before processing power_down |
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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@codeaurora.org> > --- > 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
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