From: Alex Bee knaerzche@gmail.com
[ Upstream commit f3bc07eba481942a246926c5b934199e7ccd567b ]
Currently it66121_probe returns -EPROBE_DEFER if the there is no remote endpoint found in the device tree which doesn't seem helpful, since this is not going to change later and it is never checked if the next bridge has been initialized yet. It will fail in that case later while doing drm_bridge_attach for the next bridge in it66121_bridge_attach.
Since the bindings documentation for it66121 bridge driver states there has to be a remote endpoint defined, its safe to return -EINVAL in that case. This additonally adds a check, if the remote endpoint is enabled and returns -EPROBE_DEFER, if the remote bridge hasn't been initialized (yet).
Fixes: 988156dc2fc9 ("drm: bridge: add it66121 driver") Signed-off-by: Alex Bee knaerzche@gmail.com Signed-off-by: Robert Foss robert.foss@linaro.org Link: https://patchwork.freedesktop.org/patch/msgid/20210918140420.231346-1-knaerz... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/bridge/ite-it66121.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/bridge/ite-it66121.c b/drivers/gpu/drm/bridge/ite-it66121.c index 9dc41a7b91362..06b59b422c696 100644 --- a/drivers/gpu/drm/bridge/ite-it66121.c +++ b/drivers/gpu/drm/bridge/ite-it66121.c @@ -918,11 +918,23 @@ static int it66121_probe(struct i2c_client *client, return -EINVAL;
ep = of_graph_get_remote_node(dev->of_node, 1, -1); - if (!ep) - return -EPROBE_DEFER; + if (!ep) { + dev_err(ctx->dev, "The endpoint is unconnected\n"); + return -EINVAL; + } + + if (!of_device_is_available(ep)) { + of_node_put(ep); + dev_err(ctx->dev, "The remote device is disabled\n"); + return -ENODEV; + }
ctx->next_bridge = of_drm_find_bridge(ep); of_node_put(ep); + if (!ctx->next_bridge) { + dev_dbg(ctx->dev, "Next bridge not found, deferring probe\n"); + return -EPROBE_DEFER; + }
if (!ctx->next_bridge) return -EPROBE_DEFER;