Re: [PATCH] software node: balance refcount for managed sw nodes

Laurentiu Tudor
2021-07-19T12:00:27Z

On 7/16/2021 8:21 PM, Jon Nettleton wrote:
> On Fri, Jul 16, 2021 at 2:17 PM Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
>>
>> On Fri, Jul 16, 2021 at 01:16:02PM +0300, laurentiu.tudor@nxp.com wrote:
>>> From: Laurentiu Tudor <laurentiu.tudor@nxp.com>
>>>
>>> software_node_notify(), on KOBJ_REMOVE drops the refcount twice on managed
>>> software nodes, thus leading to underflow errors. Balance the refcount by
>>> bumping it in the device_create_managed_software_node() function.
>>>
>>> The error [1] was encountered after adding a .shutdown() op to our
>>> fsl-mc-bus driver.
>>
>> Looking into the history of adding ->shutdown() to dwc3 driver (it got reverted
>> later on), I can tell that probably something is wrong in the ->shutdown()
>> method itself.
>>
>> --
>> With Best Regards,
>> Andy Shevchenko
>>
>>
>
> Isn't the other alternative to just remove the second kobject_put from
> KOBJ_REMOVE ?
>

Or maybe on top of Heikki's suggestion, replace the calls to
sysfs_create_link() from KOBJ_ADD with sysfs_create_link_nowarn()?

---
Best Regards, Laurentiu