Re: [PATCH 15/37] drm/display: bridge-connector: allocate the connector dynamically

[Luca Ceresoli]

Hi Maxime,

thanks for the feedback.

On Wed Jun 24, 2026 at 1:48 PM CEST, Maxime Ripard wrote:
> On Fri, Jun 12, 2026 at 02:44:43PM +0200, Luca Ceresoli wrote:
>> On Mon Jun 8, 2026 at 1:46 PM CEST, Maxime Ripard wrote:
>> > On Tue, May 19, 2026 at 12:37:32PM +0200, Luca Ceresoli wrote:
>> >> Currently the drm_bridge_connector has an embedded drm_connector, so their
>> >> allocation lifetimes are tied to each other. This is insufficient to
>> >> support DRM bridge hotplugging, which requires the connector to be added
>> >> and removed dynamically at runtime multiple times based on hotplug/unplug
>> >> events while the drm_bridge_connector is persistent.
>> >>
>> >> Moreover the drm_connector is exposed to user space and thus an ongoing
>> >> operation (e.g. an ioctl) might last for an arbitrarily long time even
>> >> after the hardware gets removed. This means a new connector might have to
>> >> be added when the previous one is still referenced by user space.
>> >>
>> >> In preparation to handle hotplug, allocate the drm-connector dynamically,
>> >> to allow:
>> >>
>> >>  * creating and destroying a connector multiple times during a single
>> >>    drm_bridge_connector lifetime
>> >>  * creating a new connector even though the previous one is still in use
>> >>    and thus still refcounted and not yet freed
>> >>
>> >> This commit does not introduce the actions in the two bullets (it will
>> >> happen in a later commit), it only moves to dynamic APIs for connector
>> >> allocation and init.
>> >>
>> >> Signed-off-by: Luca Ceresoli <luca.ceresoli@xxxxxxxxxxx>
>> >
>> > I think this patch should be split in half, with the switch to using
>> > destroy first, and then the actual move to the dynamically allocated
>> > connector API.
>>
>> Is it doable? drm_connector_dynamic_init() mandates a .destroy callback,
>> drm_connector_init() forbids it.
>
> drmm_connector_init forbids it. drm_connector_init mandates it.

Something bogus in my reply, sorry. :)

So you mean splitting in:

 * first patch: move from drmm_connector[_hdmi]_init() to
   drm_connector[_hdmi]_init() and add a .destroy
 * second patch: move from drm_connector[_hdmi]_init() to
   drm_connector[_hdmi]_dynamic_init() +
   drm_connector_dynamic_register/unregister()

?

Luca

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