Re: [PATCH v3 2/7] mfd: retu: Add OF device ID table

From: Javier Martinez Canillas
Date: Mon Apr 03 2017 - 18:25:08 EST


[adding OMAP folks to cc list]

Hello Rob,

On 04/03/2017 06:20 PM, Rob Herring wrote:
> On Mon, Apr 03, 2017 at 11:45:14AM -0400, Javier Martinez Canillas wrote:
>> Hello Lee,
>>
>> On 04/03/2017 07:15 AM, Lee Jones wrote:
>>
>> [snip]
>>
>>>>
>>>> +static const struct of_device_id retu_of_match[] = {
>>>> + { .compatible = "nokia,retu-mfd" },
>>>> + { .compatible = "nokia,tahvo-mfd" },
>>>
>>> Please drop the "-mfd".
>>>
>>
>> Yes, I also didn't like it but I didn't want to change it since that would
>> mean that backward compatiblity and bisect-ability will be broken by this
>> change.
>>
>> In other words, just adding a vendor prefix won't cause an issue if patches
>> are merged independently since if DTS patches are merged before, the driver
>> will still lookup using the I2C device ID table. And if the drivers patches
>> are picked before, the DTS will match using the OF device ID table.
>>
>> But changing to "nokia,retu" and "nokia,tahvo" means that you will need to
>> pick all patches and also that the DTS and drivers changes will have to be
>> done in the same patch. If you are OK with that, then I can change in the
>> next version.
>
> tahvo is not documented nor used in any dts (in the kernel at least).
> retu is used by 1 board and happened to work, but was never documented.
> So I think it is okay to change unless the N800 folks object.
>

I'm fine with changing it (in fact I just want to fix the I2C of modalias
reporting). Does this mean that backward compatibility and bisect-ability
should be preserved? Or it's OK to split the changes in different patches?

> Rob
>

Best regards,
---
Javier Martinez Canillas
Open Source Group
Samsung Research America