Reviewed-by: Lyude Paul lyude@redhat.com

On Tue, 2019-09-17 at 14:09 +0200, Daniel Vetter wrote:

Current code is quite a mess unfortunately, so also add a todo.rst entry to maybe fix it up eventually.

Cc: Michel Dänzer michel@daenzer.net Signed-off-by: Daniel Vetter daniel.vetter@intel.com

---

Documentation/gpu/todo.rst | 12 ++++++++++++ drivers/gpu/drm/drm_connector.c | 10 ++++++++-- drivers/gpu/drm/drm_dp_helper.c | 8 ++++++++ 3 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst index 32787acff0a8..8dc147c93c9c 100644 --- a/Documentation/gpu/todo.rst +++ b/Documentation/gpu/todo.rst @@ -284,6 +284,18 @@ drm_fb_helper tasks removed: drm_fb_helper_single_add_all_connectors(), drm_fb_helper_add_one_connector() and drm_fb_helper_remove_one_connector().

+connector register/unregister fixes +-----------------------------------

+- For most connectors it's a no-op to call drm_connector_register/unregister

• directly from driver code, drm_dev_register/unregister take care of this
• already. We can remove all of them.

+- For dp drivers it's a bit more a mess, since we need the connector to be

• registered when calling drm_dp_aux_register. Fix this by instead calling
• drm_dp_aux_init, and moving the actual registering into a late_register
• callback as recommended in the kerneldoc.

Core refactorings

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c index 4c766624b20d..cd5048ceab1d 100644 --- a/drivers/gpu/drm/drm_connector.c +++ b/drivers/gpu/drm/drm_connector.c @@ -480,7 +480,10 @@ EXPORT_SYMBOL(drm_connector_cleanup);

• drm_connector_register - register a connector
• @connector: the connector to register

• • Register userspace interfaces for a connector

• • Register userspace interfaces for a connector. Only call this for

connectors

• • which can be hotplugged after drm_dev_register() has been called

already,

• • e.g. DP MST connectors. All other connectors will be registered

automatically

• • when calling drm_dev_register().
  • Returns:
  • Zero on success, error code on failure.

@@ -526,7 +529,10 @@ EXPORT_SYMBOL(drm_connector_register);

• drm_connector_unregister - unregister a connector
• @connector: the connector to unregister

• • Unregister userspace interfaces for a connector

• • Unregister userspace interfaces for a connector. Only call this for
• • connectors which have registered explicitly by calling

drm_dev_register(),

• • since connectors are unregistered automatically when

drm_dev_unregister() is

• • called.
  */

void drm_connector_unregister(struct drm_connector *connector) { diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index ffc68d305afe..f373798d82f6 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -1109,6 +1109,14 @@ EXPORT_SYMBOL(drm_dp_aux_init);

• @aux: DisplayPort AUX channel
• Automatically calls drm_dp_aux_init() if this hasn't been done yet.

• • This should only be called when the underlying &struct drm_connector is
• • initialiazed already. Therefore the best place to call this is from
• • &drm_connector_funcs.late_register. Not that drivers which don't follow

this

• • will Oops when CONFIG_DRM_DP_AUX_CHARDEV is enabled.
• • Drivers which need to use the aux channel before that point (e.g. at

driver

• • load time, before drm_dev_register() has been called) need to call
• • drm_dp_aux_init().
  • Returns 0 on success or a negative error code on failure.
  */