drm_kms_helper_poll_init(9) initialize and enable output polling


void drm_kms_helper_poll_init(struct drm_device * dev);





This function intializes and then also enables output polling support for dev. Drivers which do not have reliable hotplug support in hardware can use this helper infrastructure to regularly poll such connectors for changes in their connection state.

Drivers can control which connectors are polled by setting the DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On connectors where probing live outputs can result in visual distortion drivers should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this. Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are completely ignored by the polling logic.

Note that a connector can be both polled and probed from the hotplug handler, in case the hotplug interrupt is known to be unreliable.


Jesse Barnes <[email protected]>
Intel Corporation,         

Initial version

Laurent Pinchart <[email protected]>
Ideas on board SPRL,         

Driver internals

Daniel Vetter <[email protected]>
Intel Corporation,         

Contributions all over the place

Lukas Wunner <[email protected]>

vga_switcheroo documentation