[PATCH 5.14 340/849] drm/bridge: it66121: Wait for next bridge to be probed

[Greg Kroah-Hartman]

From: Paul Cercueil <paul@xxxxxxxxxxxxxxx>

[ Upstream commit 8b03e3fc79189b17d31a82f5e175698802a11e87 ]

If run before the next bridge is initialized, of_drm_find_bridge() will
give us a NULL pointer.

If that's the case, return -EPROBE_DEFER; we may have more luck next
time.

Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
Fixes: 988156dc2fc9 ("drm: bridge: add it66121 driver")
Reviewed-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
Signed-off-by: Robert Foss <robert.foss@xxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20210827163956.27517-2-paul@xxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/gpu/drm/bridge/ite-it66121.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/bridge/ite-it66121.c b/drivers/gpu/drm/bridge/ite-it66121.c
index b130d01147c6c..9dc41a7b91362 100644
--- a/drivers/gpu/drm/bridge/ite-it66121.c
+++ b/drivers/gpu/drm/bridge/ite-it66121.c
@@ -924,6 +924,9 @@ static int it66121_probe(struct i2c_client *client,
 	ctx->next_bridge = of_drm_find_bridge(ep);
 	of_node_put(ep);
 
+	if (!ctx->next_bridge)
+		return -EPROBE_DEFER;
+
 	i2c_set_clientdata(client, ctx);
 	mutex_init(&ctx->lock);
 
-- 
2.33.0