Document how to perform a forced probe, and when should user-space do it.
Signed-off-by: Simon Ser contact@emersion.fr Cc: Daniel Vetter daniel@ffwll.ch Cc: Pekka Paalanen ppaalanen@gmail.com --- include/uapi/drm/drm_mode.h | 13 +++++++++++++ 1 file changed, 13 insertions(+)
diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h index 5ad10ab2a577..09647b799f39 100644 --- a/include/uapi/drm/drm_mode.h +++ b/include/uapi/drm/drm_mode.h @@ -368,6 +368,19 @@ enum drm_mode_subconnector { #define DRM_MODE_CONNECTOR_WRITEBACK 18 #define DRM_MODE_CONNECTOR_SPI 19
+/** + * struct drm_mode_get_connector - get connector metadata + * + * If the @count_modes field is set to zero, the kernel will perform a forced + * probe on the connector to refresh the connector status, modes and EDID. + * A forced-probe can be slow and the ioctl will block. + * + * User-space shouldn't need to force-probe connectors in general: the kernel + * will automatically take care of probing connectors that don't support + * hot-plug detection when appropriate. However, user-space may force-probe + * connectors on user request (e.g. clicking a "Scan connectors" button, or + * opening a UI to manage screens). + */ struct drm_mode_get_connector {
__u64 encoders_ptr;