Re: [PATCH] ACPI / GED: unregister interrupts during shutdown

From: Sinan Kaya
Date: Thu Dec 07 2017 - 09:52:15 EST


Rafael,

On 12/7/2017 8:00 AM, Rafael J. Wysocki wrote:
>> Just don't use devm_request_threaded_irq()? :)
>>
>> Seriously, those are just "helper" functions if your code happens to
>> follow the pattern they provide, if not, then don't use them, it's not
>> that hard to provide the correct code to unwind things properly by "open
>> coding" this logic as needed.
>>
>> The devm_*irq() functions are known for not being able to be used all of
>> the time for lots of shutdown and cleanup issues, this isn't the first
>> time it has happened, which is why we are very careful when taking
>> "cleanup" patches that use those functions.
> I see, thanks for the clarification.
>
> OK, we'll need to rework the driver somewhat, then.

Even if we got rid of devm_*irq() functions, I see that the free_irq() function
requires dev_id argument.

* There can be multiple actions per IRQ descriptor, find the right
* one based on the dev_id:

I still need to keep track of the dev_ids attached to request_irq() functions.

My take away from the discussion is:
1. don't use devm family of functions for IRQ registration/free
2. still keep track of the events
3. call free_irq on shutdown.

Do you have something else on your mind?

Sinan

--
Sinan Kaya
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.