Re: [PATCH 26/37] drm: event-notifier: add mechanism to notify about hotplug events

["Luca Ceresoli" <luca.ceresoli@bootlin.com>]

On Mon Jun 8, 2026 at 2:13 PM CEST, Maxime Ripard wrote:
> On Tue, May 19, 2026 at 12:37:43PM +0200, Luca Ceresoli wrote:
>> In preparation for supporting DRM bridge hotplug, add an event notifier to
>> allow interested parties to be notified about events they need to react to.
>>
>> For the initial implementation of bridge hotplug, two events are needed:
>> bridge detach (happening in drm_bridge.c) and MIPI device attach to MIPI
>> host (happening in drm_mipi_dsi.c).
>>
>> For this reason implement the event notifier in a new common file that
>> event producers can easily use to send events.
>>
>> Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
>
> So, you claim in the commit message that it's about a hotplug event, but
> the only events are the bridge being attached and detached, so not a
> hotplug event?
>
> And why a bridge would want to be notified that itself (or another?)
> bridge is being attached or detached?
>
> You need documentation, and a more descriptive commit message.

Yes.

But before that I need a decision about the scope we want to give to this
notifier. It is a very generic module, with basically no dependencies, so
people will try to add more unrelated events and we'd need to set a
boundary.

Options:

 * Should it be for hotplug-related events only?
 * Should it be for any DRM event that needs notifications?
 * Something else?

I'm happy to write that in the docs and commit message once it's agreed, so
any comments would be welcome right now.

Luca

--
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com