Re: [PATCH v6 1/8] i2c: core: let adapters be notified of client attach/detach

Tomi Valkeinen
2023-01-08T09:25:13Z

On 08/01/2023 05:13, Laurent Pinchart wrote:
> Hi Tomi,
>
> Thank you for the patch.
>
> On Thu, Jan 05, 2023 at 04:03:00PM +0200, Tomi Valkeinen wrote:
>> From: Luca Ceresoli <luca@lucaceresoli.net>
>>
>> An adapter might need to know when a new device is about to be
>> added. This will soon bee needed to implement an "I2C address
>> translator" (ATR for short), a device that propagates I2C transactions
>> with a different slave address (an "alias" address). An ATR driver
>> needs to know when a slave is being added to find a suitable alias and
>> program the device translation map.
>>
>> Add an attach/detach callback pair to allow adapter drivers to be
>> notified of clients being added and removed.
>
> I've asked in the review of v6 if we could instead use the
> BUS_NOTIFY_ADD_DEVICE and BUS_NOTIFY_DEL_DEVICE bus notifiers. There's
> been a follow up discussion with Andy, but no reply from you AFAICS.
> Have you given this a try ? It's not a mandatory requirement, but if it
> can't be done (or shouldn't be done), I'd like to know why.

Sorry, I meant to mention this in the cover letter, but forgot:

I haven't looked at the bus notifiers yet, but will have a look. I
wanted to send a new revision due to the large amount of changes already
done.

Tomi