On Wed, Aug 24, 2016 at 02:05:59PM +0200, Andrea Merello wrote:
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.
Suggested-by: Daniel Vetter daniel@ffwll.ch Suggested-by: Lucas Stach l.stach@pengutronix.de Signed-off-by: Andrea Merello andrea.merello@gmail.com Cc: Archit Taneja architt@codeaurora.org Cc: David Airlie airlied@linux.ie Cc: Daniel Vetter daniel@ffwll.ch Cc: Lucas Stach l.stach@pengutronix.de
drivers/gpu/drm/drm_bridge.c | 26 ++++++++++++++++++++++++++ include/drm/drm_crtc.h | 17 +++++++++++++++++ 2 files changed, 43 insertions(+)
diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index 2555430..a77b3e0 100644 --- a/drivers/gpu/drm/drm_bridge.c +++ b/drivers/gpu/drm/drm_bridge.c @@ -125,6 +125,32 @@ 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
Empty line, and we do full sentences (including capitalization and punctuation) in the full kernel-doc paragraphs.
- */
+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
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index b618b50..5e25e23 100644 --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -1765,9 +1765,25 @@ struct drm_plane {
- @attach: Called during drm_bridge_attach
*/ struct drm_bridge_funcs {
- /**
* @attach:** This callback is invoked whenever our bridge is being attached.
... attached to a &drm_encoder. Similar for @detach.
Also I think we should mentation that these callbacks are optional, like with the others. Just noticed that that remark is missing for @mode_fixup, can you pls add it too?
lgtm otherwise. -Daniel
** RETURNS:** Zero on success, error code on failure*/int (*attach)(struct drm_bridge *bridge);
/**
* @detach:** This callback is invoked whenever our bridge is being detached.*/void (*detach)(struct drm_bridge *bridge);
/**
- @mode_fixup:
- This callback is used to validate and adjust a mode. The paramater
@@ -3196,6 +3212,7 @@ extern int drm_bridge_add(struct drm_bridge *bridge); extern void drm_bridge_remove(struct drm_bridge *bridge); extern struct drm_bridge *of_drm_find_bridge(struct device_node *np); extern int drm_bridge_attach(struct drm_device *dev, struct drm_bridge *bridge); +extern void drm_bridge_detach(struct drm_bridge *bridge);
bool drm_bridge_mode_fixup(struct drm_bridge *bridge, const struct drm_display_mode *mode, -- 2.7.4