Re: [PATCH 1/6] mmc: dw_mmc: remove the deprecated "clock-freq-min-max" property

From: Andy Shevchenko
Date: Fri Feb 23 2018 - 11:16:46 EST


On Fri, Feb 23, 2018 at 4:19 PM, Shawn Lin <shawn.lin@xxxxxxxxxxxxxx> wrote:
> On 2018/2/23 21:27, Andy Shevchenko wrote:
>> On Fri, Feb 23, 2018 at 8:41 AM, Jaehoon Chung <jh80.chung@xxxxxxxxxxx>
>> wrote:
>>>
>>> 'clock-freq-min-max' property had already deprecated.
>>> Remove the 'clock-freq-min-max' property that is kept to maintain
>>> the compatibility.
>>
>>
>> Removing a property without telling the user what to expect is a bad
>> idea and ABI breakage.
>>
>
> What's the general process to remove a property?
>
> I guess we should do:
> 1) deprecate it in the first place and remove it from all upstream DT
> 2) wait some long enough days for expecting the stale of all old DTB
> containing that property
> 3) remove the functionality of the deprecated property from the driver
> but still leave some warning there
> 4) remove the left warning finally

I don't know. Perhaps Rob can shed a light here.
But I would really OK with removal of some of such properties from
some drivers where it's more burden to keep them.

> And for the ABI breakage, we should add something in Documentation/ABI
> /obsolete or Documentation/ABI/removed ?

--
With Best Regards,
Andy Shevchenko