[PATCH v3 4/4] drm/omap: dss: convert to of_drm_find_and_get_bridge()

Luca Ceresoli
2026-03-18T09:40:07Z

of_drm_find_and_get_bridge() which gets a bridge reference, and ensure it
is put when done.

omapdss_device_init_output() can take one bridge pointer in out->bridge or
two pointers in out->bridge and out->next_bridge. Ensure each has a
corresponding drm_bridge_get() and add drm_bridge_put() calls in the
cleanup code.

Also slightly change the initial code assigning out->panel and out->bridge
to ensure and clarify that either out->panel or out->bridge is set in the
function prologue, not both. If both were set, the 'if (out->panel){...}'
code that follows would overwrite out->bridge without having put the
reference.

Finally, take a reference in case a panel_bridge is added using
drm_panel_bridge_add(). This ensures we always need to put a reference,
which came either from of_drm_find_and_get_bridge() or by the
drm_panel_bridge_add+drm_bridge_get() branch.

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
---
drivers/gpu/drm/omapdrm/dss/output.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/omapdrm/dss/output.c b/drivers/gpu/drm/omapdrm/dss/output.c
index 7378e855c278..ca891aba3820 100644
--- a/drivers/gpu/drm/omapdrm/dss/output.c
+++ b/drivers/gpu/drm/omapdrm/dss/output.c
@@ -30,11 +30,13 @@ int omapdss_device_init_output(struct omap_dss_device *out,
return 0;
}

- out->bridge = of_drm_find_bridge(remote_node);
out->panel = of_drm_find_panel(remote_node);
if (IS_ERR(out->panel))
out->panel = NULL;

+ if (!out->panel)
+ out->bridge = of_drm_find_and_get_bridge(remote_node);
+
of_node_put(remote_node);

if (out->panel) {
@@ -49,7 +51,7 @@ int omapdss_device_init_output(struct omap_dss_device *out,
goto error;
}

- out->bridge = bridge;
+ out->bridge = drm_bridge_get(bridge);
}

if (local_bridge) {
@@ -59,7 +61,7 @@ int omapdss_device_init_output(struct omap_dss_device *out,
}

out->next_bridge = out->bridge;
- out->bridge = local_bridge;
+ out->bridge = drm_bridge_get(local_bridge);
}

if (!out->bridge) {
@@ -79,6 +81,9 @@ void omapdss_device_cleanup_output(struct omap_dss_device *out)
if (out->bridge && out->panel)
drm_panel_bridge_remove(out->next_bridge ?
out->next_bridge : out->bridge);
+
+ drm_bridge_put(out->next_bridge);
+ drm_bridge_put(out->bridge);
}

void dss_mgr_set_timings(struct omap_dss_device *dssdev,

--
2.53.0