Re: [PATCH 3/3] extcon: Simplify extcon_dev_register() prototype by removing unnecessary parameter

[Chanwoo Choi <cw00.choi@samsung.com>]

On 09/04/2013 12:57 AM, Greg KH wrote:
> On Mon, Sep 02, 2013 at 10:13:44AM +0900, Chanwoo Choi wrote:
>> Hi Greg,
>>
>> On 09/02/2013 09:40 AM, Greg KH wrote:
>>> On Mon, Sep 02, 2013 at 09:20:08AM +0900, Chanwoo Choi wrote:
>>>> This patch remove extcon_dev_register()'s second parameter which means
>>>> the pointer of parent device to simplify prototype of this function.
>>>
>>> No, please don't.  You want the parent to be passed in, as the core
>>> needs it when it is registered with the system, otherwise it will not
>>> show up in sysfs properly (i.e. you can't set it afterwards.)
>>
>> Currently, each extcon driver have allocated memory for extcon device
>> by using devm_kzalloc() in each extcon device driver.
> 
> That seems backwards, the extcon core should be the one doing the
> allocation, and ownership of the device, like all other subsystem cores
> do.  That makes the driver logic much simpler, and the lifetime
> ownership correct (i.e. what happens when a device is unbound from a
> driver by userspace?  The driver can't control the device memory
> anymore...)
> 

OK,
The extcon core will control memory allocation instead of extcon device driver
as following.
- devm_extcon_allocate_device(struct device *dev)

I'll complete this feature about memory allocation for extcon device
and resend it again. Thanks.

Best Regards,
Chanwoo Choi