[PATCH] i3c: master: Add WO sysfs option to re-DDA bus.

[Frank Li]

On Thu, Jan 22, 2026 at 04:47:23PM +0100, David Nyström wrote:
>
> On Thu, 22 Jan 2026, Wolfram Sang wrote:
>
> > On Thu, Jan 22, 2026 at 12:36:30PM +0100, David Nyström wrote:
> > > Add ability to rescan the i3c bus from userspace, i.e. provoke a DDA.
> >
> > Your are describing what you do but what is missing is why you want the
> > change. What is the use case?
>
> The usecase would be an i3cdev userspace driver for a device with broken
> hotjoin support.
> The device requires FW loading(userspace framework) before it will respond
> to DAA, and is thus not registered during initial bus probe.
> I guess a similiar problem would apply if hot-join is bus disabled via
> sysfs, and resume hook DDA runs before i3c devices are powered up properly.
>
> A bit of a niche usecase, I know.
> I found it to be usable though, but perhaps this is better placed in debugfs
> in case its too much of an eyesore for the stable ABI.

It is useful. Please improve commit message.

Frank