diff mbox series

[v3,21/22] drm/bridge: panel: convert to devm_drm_bridge_alloc() API

Message ID 20250509-drm-bridge-convert-to-alloc-api-v3-21-b8bc1f16d7aa@bootlin.com
State New
Headers show
Series [v3,01/22] Revert "drm/exynos: mic: convert to devm_drm_bridge_alloc() API" | expand

Commit Message

Luca Ceresoli May 9, 2025, 1:53 p.m. UTC
This is the new API for allocating DRM bridges.

The devm lifetime management of this driver is peculiar. The underlying
device for the panel_bridge is the panel, and the devm lifetime is tied the
panel device (panel->dev). However the panel_bridge allocation is not
performed by the panel driver, but rather by a separate entity (typically
the previous bridge in the encoder chain).

Thus when that separate entity is destroyed, the panel_bridge is not
removed automatically by devm, so it is rather done explicitly by calling
drm_panel_bridge_remove(). This is the function that does devm_kfree() the
panel_bridge in current code, so update it as well to put the bridge
reference instead.

This is a temporary solution until the panel lifetime is reworked, which
should make this workaround unnecessary, so add a comment to clarify that.

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>

---

Changes in v3:
- add TODO to remove devm_drm_put_bridge(), update commit message
- fix typo in commit message

Changes in v2: none
---
 drivers/gpu/drm/bridge/panel.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/bridge/panel.c b/drivers/gpu/drm/bridge/panel.c
index 79b009ab9396048eac57ad47631a902e949d77c6..6cbbfb1381a4a75fbc3acf6e6c5361202627e740 100644
--- a/drivers/gpu/drm/bridge/panel.c
+++ b/drivers/gpu/drm/bridge/panel.c
@@ -287,15 +287,14 @@  struct drm_bridge *drm_panel_bridge_add_typed(struct drm_panel *panel,
 	if (!panel)
 		return ERR_PTR(-EINVAL);
 
-	panel_bridge = devm_kzalloc(panel->dev, sizeof(*panel_bridge),
-				    GFP_KERNEL);
-	if (!panel_bridge)
-		return ERR_PTR(-ENOMEM);
+	panel_bridge = devm_drm_bridge_alloc(panel->dev, struct panel_bridge, bridge,
+					     &panel_bridge_bridge_funcs);
+	if (IS_ERR(panel_bridge))
+		return (void *)panel_bridge;
 
 	panel_bridge->connector_type = connector_type;
 	panel_bridge->panel = panel;
 
-	panel_bridge->bridge.funcs = &panel_bridge_bridge_funcs;
 	panel_bridge->bridge.of_node = panel->dev->of_node;
 	panel_bridge->bridge.ops = DRM_BRIDGE_OP_MODES;
 	panel_bridge->bridge.type = connector_type;
@@ -327,7 +326,8 @@  void drm_panel_bridge_remove(struct drm_bridge *bridge)
 	panel_bridge = drm_bridge_to_panel_bridge(bridge);
 
 	drm_bridge_remove(bridge);
-	devm_kfree(panel_bridge->panel->dev, bridge);
+	/* TODO remove this after reworking panel_bridge lifetime */
+	devm_drm_put_bridge(panel_bridge->panel->dev, bridge);
 }
 EXPORT_SYMBOL(drm_panel_bridge_remove);