[PATCH v3 3/4] drm/bridge: Add devm_drm_bridge_add()

From: Douglas Anderson
Date: Tue May 10 2022 - 15:30:16 EST


This adds a devm managed version of drm_bridge_add(). Like other
"devm" function listed in drm_bridge.h, this function takes an
explicit "dev" to use for the lifetime management. A few notes:
* In general we have a "struct device" for bridges that makes a good
candidate for where the lifetime matches exactly what we want.
* The "bridge->dev->dev" device appears to be the encoder
device. That's not the right device to use for lifetime management.

Suggested-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
---

Changes in v3:
- Patch ("drm/bridge: Add devm_drm_bridge_add()") new for v3.

drivers/gpu/drm/drm_bridge.c | 23 +++++++++++++++++++++++
include/drm/drm_bridge.h | 1 +
2 files changed, 24 insertions(+)

diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index c96847fc0ebc..e275b4ca344b 100644
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -170,6 +170,29 @@ void drm_bridge_add(struct drm_bridge *bridge)
}
EXPORT_SYMBOL(drm_bridge_add);

+static void drm_bridge_remove_void(void *bridge)
+{
+ drm_bridge_remove(bridge);
+}
+
+/**
+ * devm_drm_bridge_add - devm managed version of drm_bridge_add()
+ *
+ * @dev: device to tie the bridge lifetime to
+ * @bridge: bridge control structure
+ *
+ * This is the managed version of drm_bridge_add() which automatically
+ * calls drm_bridge_remove() when @dev is unbound.
+ *
+ * Return: 0 if no error or negative error code.
+ */
+int devm_drm_bridge_add(struct device *dev, struct drm_bridge *bridge)
+{
+ drm_bridge_add(bridge);
+ return devm_add_action_or_reset(dev, drm_bridge_remove_void, bridge);
+}
+EXPORT_SYMBOL(devm_drm_bridge_add);
+
/**
* drm_bridge_remove - remove the given bridge from the global bridge list
*
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index f27b4060faa2..42aec8612f37 100644
--- a/include/drm/drm_bridge.h
+++ b/include/drm/drm_bridge.h
@@ -796,6 +796,7 @@ drm_priv_to_bridge(struct drm_private_obj *priv)
}

void drm_bridge_add(struct drm_bridge *bridge);
+int devm_drm_bridge_add(struct device *dev, struct drm_bridge *bridge);
void drm_bridge_remove(struct drm_bridge *bridge);
int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
struct drm_bridge *previous,
--
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