Re: [PATCH v10 01/11] usb: typec: Add notifier functions

[Chaoyi Chen]

Hi Greg,

On 11/21/2025 10:07 PM, Greg Kroah-Hartman wrote:
> On Thu, Nov 20, 2025 at 10:23:33AM +0800, Chaoyi Chen wrote:
> > From: Chaoyi Chen <chaoyi.chen@xxxxxxxxxxxxxx>
> >
> > Some other part of kernel may want to know the event of typec bus.
> Be specific, WHAT part of the kernel will need to know this?

For now, it is DRM.


> And why a new notifier, why not just use the existing notifiers that you
> already have?  And what is this going to be used for?

We have discussed this before, but the current bus notifier cannot achieve the expected notification [0].

[0] https://lore.kernel.org/all/aPsuLREPS_FEV3DS@xxxxxxxxxxxxxxxxx/


> Notifiers are a pain, and should almost never be added.  Use real
> function calls instead.

In v6, I used direct function calls, but had to switch to notifiers because couldn't resolve the dependencies between DRM and Type-C [1]. Do you have any good ideas? Thank you.

[1] https://lore.kernel.org/all/aPYImGmesrZWwyqh@xxxxxxxxxxxxxxxxx/


> thanks,
>
> greg k-h
--
Best,
Chaoyi