From cf3bef95e1014233cb1ce89da8cfa5cd22e7412c Mon Sep 17 00:00:00 2001 From: Andrea Merello Date: Thu, 25 Aug 2016 11:04:32 +0200 Subject: drm/bridge: introduce bridge detaching mechanism Up to now, once a bridge has been attached to a DRM device, it cannot be undone. In particular you couldn't rmmod/insmod a DRM driver that uses a bridge, because the bridge would remain bound to the first (dead) driver instance. This patch fixes this by introducing drm_encoder_detach() and a ->detach callback in drm_bridge_funcs for the bridge to be notified about detaches. It's DRM/KMS driver responsibility to call drm_encoder_detach(). While adding the bridge detach callback, with its kerneldoc, I also added kerneldoc for attach callback. Few other kerneldocs fixes around there are included. Suggested-by: Daniel Vetter Suggested-by: Lucas Stach Signed-off-by: Andrea Merello Cc: Archit Taneja Cc: David Airlie Cc: Daniel Vetter Cc: Lucas Stach Signed-off-by: Archit Taneja Link: http://patchwork.freedesktop.org/patch/msgid/1472115874-6219-1-git-send-email-andrea.merello@gmail.com --- drivers/gpu/drm/drm_bridge.c | 29 +++++++++++++++++++++++++++-- 1 file changed, 27 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index 2555430..4840466 100644 --- a/drivers/gpu/drm/drm_bridge.c +++ b/drivers/gpu/drm/drm_bridge.c @@ -98,11 +98,11 @@ EXPORT_SYMBOL(drm_bridge_remove); * @dev: DRM device * @bridge: bridge control structure * - * called by a kms driver to link one of our encoder/bridge to the given + * Called by a kms driver to link one of our encoder/bridge to the given * bridge. * * Note that setting up links between the bridge and our encoder/bridge - * objects needs to be handled by the kms driver itself + * objects needs to be handled by the kms driver itself. * * RETURNS: * Zero on success, error code on failure @@ -125,6 +125,31 @@ int drm_bridge_attach(struct drm_device *dev, struct drm_bridge *bridge) EXPORT_SYMBOL(drm_bridge_attach); /** + * drm_bridge_detach - deassociate given bridge from its DRM device + * + * @bridge: bridge control structure + * + * Called by a kms driver to unlink the given bridge from its DRM device. + * + * Note that tearing down links between the bridge and our encoder/bridge + * objects needs to be handled by the kms driver itself. + */ +void drm_bridge_detach(struct drm_bridge *bridge) +{ + if (WARN_ON(!bridge)) + return; + + if (WARN_ON(!bridge->dev)) + return; + + if (bridge->funcs->detach) + bridge->funcs->detach(bridge); + + bridge->dev = NULL; +} +EXPORT_SYMBOL(drm_bridge_detach); + +/** * DOC: bridge callbacks * * The &drm_bridge_funcs ops are populated by the bridge driver. The DRM -- cgit v1.1