When registering a connector, the kernel sends a hotplug uevent in
drm_connector_register(). When unregistering a connector, drivers
are expected to send a uevent as well. However, user-space has no way
to figure out that the connector isn't registered anymore: it'll still
be reported in GETCONNECTOR IOCTLs.
The documentation for DRM_CONNECTOR_UNREGISTERED states:
> The connector […] has since been unregistered and removed from
> userspace, or the connector was unregistered before it had a chance
> to be exposed to userspace
Signed-off-by: Simon Ser <contact@emersion.fr>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220801133754.461037-1-contact@emersion.fr
count = 0;
connector_id = u64_to_user_ptr(card_res->connector_id_ptr);
drm_for_each_connector_iter(connector, &conn_iter) {
+ if (connector->registration_state != DRM_CONNECTOR_REGISTERED)
+ continue;
+
/* only expose writeback connectors if userspace understands them */
if (!file_priv->writeback_connectors &&
(connector->connector_type == DRM_MODE_CONNECTOR_WRITEBACK))