linux-kernel - Re: [PATCH v1] remoteproc: core: do pm relax when not first crash

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Date:   Tue, 13 Sep 2022 19:03:32 +0800
From:   "Aiqun(Maria) Yu" <quic_aiquny@...cinc.com>
To:     Mathieu Poirier <mathieu.poirier@...aro.org>
CC:     <linux-remoteproc@...r.kernel.org>,
        <linux-arm-msm@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <quic_clew@...cinc.com>
Subject: Re: [PATCH v1] remoteproc: core: do pm relax when not first crash

Hi Mathieu,

pm_awake and pm_relax needed to be used as a pair. There is chance that 
pm_relax is not being called, and make the device always in cannot 
suspend state.

On 9/10/2022 3:23 AM, Mathieu Poirier wrote:
> Hi Maria,
> 
> On Fri, Sep 09, 2022 at 04:33:33PM +0800, Maria Yu wrote:
>> Even if it is not first crash, need to relax the pm
>> wakelock otherwise the device will stay awake.
>>
> 
> The goal is exactly to keep the device awake...
> 
>> Signed-off-by: Maria Yu <quic_aiquny@...cinc.com>
>> ---
>>   drivers/remoteproc/remoteproc_core.c | 1 +
>>   1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
>> index e5279ed9a8d7..30078043e939 100644
>> --- a/drivers/remoteproc/remoteproc_core.c
>> +++ b/drivers/remoteproc/remoteproc_core.c
>> @@ -1956,6 +1956,7 @@ static void rproc_crash_handler_work(struct work_struct *work)
>>   	if (rproc->state == RPROC_CRASHED || rproc->state == RPROC_OFFLINE) {
>>   		/* handle only the first crash detected */
>>   		mutex_unlock(&rproc->lock);
>> +		pm_relax(rproc->dev.parent);
> 
> If we are here it means that rproc_crash_handler_work() has already been called
> _and_ that a recovery is in process.  When the first crash handler completes
> pm_relax() will be called and the device will go to sleep as expected.
If the rproc->state cannot be changed to running state, the device will 
always be awake from this return.
Also APROC_OFFLINE state can be given in other path like an shutdown 
request is issued.

While this patch is not considering carefully as well, I think I need to 
upload a new patchset with an ordered workqueue to make each work have 
each pm_relax before return.
what do you think?
> 
> Thanks,
> Mathieu
> 
>>   		return;
>>   	}
>>   
>> -- 
>> 2.7.4
>>


-- 
Thx and BRs,
Aiqun(Maria) Yu