From: Bhaumik Bhatt <bbhatt@codeaurora.org>
To: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>,
mgautam@codeaurora.org
Cc: linux-arm-msm@vger.kernel.org, hemantk@codeaurora.org,
jhugo@codeaurora.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1 05/10] bus: mhi: core: Disable IRQs when powering down
Date: Mon, 12 Oct 2020 17:03:56 -0700 [thread overview]
Message-ID: <8b49f421f81ff850e58d14795376337b@codeaurora.org> (raw)
In-Reply-To: <20201009160216.GF4810@Mani-XPS-13-9360>
On 2020-10-09 09:02, Manivannan Sadhasivam wrote:
> On Fri, Sep 18, 2020 at 07:02:30PM -0700, Bhaumik Bhatt wrote:
>> While powering down, the device may or may not acknowledge the MHI
>> RESET issued by host for graceful shutdown scenario which can lead
>> to a rogue device sending an interrupt after the clean-up has been
>> done. This can result in a tasklet being scheduled after it has
>> been killed and access already freed memory causing a NULL pointer
>> exception. Avoid this corner case by disabling the interrupts as a
>> part of host clean up.
>>
>> Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
>> ---
>> drivers/bus/mhi/core/pm.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
>> index 1862960..3462d82 100644
>> --- a/drivers/bus/mhi/core/pm.c
>> +++ b/drivers/bus/mhi/core/pm.c
>> @@ -517,6 +517,7 @@ static void mhi_pm_disable_transition(struct
>> mhi_controller *mhi_cntrl,
>> for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
>> if (mhi_event->offload_ev)
>> continue;
>> + disable_irq(mhi_cntrl->irq[mhi_event->irq]);
>
> No need to disable irq[0]?
>
> Thanks,
> Mani
>
>> tasklet_kill(&mhi_event->task);
>> }
>>
>> --
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
>> Forum,
>> a Linux Foundation Collaborative Project
>>
This patch would disable the IRQ line and if IRQ lines are shared
between BHI
and MHI, we would not see handling of BHI related work happen.
Discussed this with Hemant and and as I am dropping the previous patch,
will update
this one to make it free_irq() instead which removes the IRQ handler and
does not
disable the interrupt line.
The function mhi_deinit_free_irq() will not be called from
mhi_power_down() and
instead, only a free for the main IRQ handler will be called.
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
Forum,
a Linux Foundation Collaborative Project
next prev parent reply other threads:[~2020-10-13 0:06 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-19 2:02 [PATCH v1 00/10] Bug fixes and improvements for MHI power operations Bhaumik Bhatt
2020-09-19 2:02 ` [PATCH v1 01/10] bus: mhi: core: Use appropriate names for firmware load functions Bhaumik Bhatt
2020-10-09 15:23 ` Manivannan Sadhasivam
2020-09-19 2:02 ` [PATCH v1 02/10] bus: mhi: core: Move to using high priority workqueue Bhaumik Bhatt
2020-10-09 15:49 ` Manivannan Sadhasivam
2020-09-19 2:02 ` [PATCH v1 03/10] bus: mhi: core: Skip device wake in error or shutdown states Bhaumik Bhatt
2020-10-09 15:54 ` Manivannan Sadhasivam
2020-09-19 2:02 ` [PATCH v1 04/10] bus: mhi: core: Use the IRQF_ONESHOT flag for the BHI interrupt line Bhaumik Bhatt
2020-10-09 15:57 ` Manivannan Sadhasivam
2020-10-09 16:04 ` Jeffrey Hugo
2020-10-12 23:52 ` Bhaumik Bhatt
2020-09-19 2:02 ` [PATCH v1 05/10] bus: mhi: core: Disable IRQs when powering down Bhaumik Bhatt
2020-10-09 16:02 ` Manivannan Sadhasivam
2020-10-13 0:03 ` Bhaumik Bhatt [this message]
2020-10-10 23:45 ` Manu Gautam
2020-09-19 2:02 ` [PATCH v1 06/10] bus: mhi: core: Improve shutdown handling after link down detection Bhaumik Bhatt
2020-10-09 16:19 ` Manivannan Sadhasivam
2020-10-13 18:40 ` Bhaumik Bhatt
2020-10-11 0:06 ` Manu Gautam
2020-09-19 2:02 ` [PATCH v1 07/10] bus: mhi: core: Move to SYS_ERROR regardless of RDDM capability Bhaumik Bhatt
2020-10-09 16:32 ` Manivannan Sadhasivam
2020-10-14 1:06 ` Bhaumik Bhatt
2020-09-19 2:02 ` [PATCH v1 08/10] bus: mhi: core: Move to an error state on any firmware load failure Bhaumik Bhatt
2020-10-09 16:42 ` Manivannan Sadhasivam
2020-10-14 1:37 ` Bhaumik Bhatt
2020-09-19 2:02 ` [PATCH v1 09/10] bus: mhi: core: Move to an error state on mission mode failure Bhaumik Bhatt
2020-10-09 16:44 ` Manivannan Sadhasivam
2020-09-19 2:02 ` [PATCH v1 10/10] bus: mhi: core: Mark device inactive soon after host issues a shutdown Bhaumik Bhatt
2020-10-09 17:18 ` Manivannan Sadhasivam
2020-10-11 0:17 ` Manu Gautam
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