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drm: of: Properly try all possible cases for bridge/panel detection

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While bridge/panel detection was initially relying on the usual
port/ports-based of graph detection, it was recently changed to
perform the lookup on any child node that is not port/ports
instead when such a node is available, with no fallback on the
usual way.

This results in breaking detection when a child node is present
but does not contain any panel or bridge node, even when the
usual port/ports-based of graph is there.

In order to support both situations properly, this commit reworks
the logic to try both options and not just one of the two: it will
only return -EPROBE_DEFER when both have failed.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Fixes: 80253168db ("drm: of: Lookup if child node has panel or bridge")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220329132732.628474-1-paul.kocialkowski@bootlin.com
This commit is contained in:
Paul Kocialkowski 2022-03-29 15:27:32 +02:00 committed by Maxime Ripard
parent c42ee39c1e
commit 67bae5f28c
No known key found for this signature in database
GPG Key ID: E3EF0D6F671851C5
1 changed files with 51 additions and 50 deletions
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101
drivers/gpu/drm/drm_of.c
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@ -219,6 +219,29 @@ int drm_of_encoder_active_endpoint(struct device_node *node,
}
EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint);
static int find_panel_or_bridge(struct device_node *node,
struct drm_panel **panel,
struct drm_bridge **bridge)
{
if (panel) {
*panel = of_drm_find_panel(node);
if (!IS_ERR(*panel))
return 0;
/* Clear the panel pointer in case of error. */
*panel = NULL;
}
/* No panel found yet, check for a bridge next. */
if (bridge) {
*bridge = of_drm_find_bridge(node);
if (*bridge)
return 0;
}
return -EPROBE_DEFER;
}
/**
* drm_of_find_panel_or_bridge - return connected panel or bridge device
* @np: device tree node containing encoder output ports
@ -241,66 +264,44 @@ int drm_of_find_panel_or_bridge(const struct device_node *np,
struct drm_panel **panel,
struct drm_bridge **bridge)
{
int ret = -EPROBE_DEFER;
struct device_node *remote;
struct device_node *node;
int ret;
if (!panel && !bridge)
return -EINVAL;
if (panel)
*panel = NULL;
if (bridge)
*bridge = NULL;
/**
* Devices can also be child nodes when we also control that device
* through the upstream device (ie, MIPI-DCS for a MIPI-DSI device).
*
* Lookup for a child node of the given parent that isn't either port
* or ports.
*/
for_each_available_child_of_node(np, remote) {
if (of_node_name_eq(remote, "port") ||
of_node_name_eq(remote, "ports"))
/* Check for a graph on the device node first. */
if (of_graph_is_present(np)) {
node = of_graph_get_remote_node(np, port, endpoint);
if (node) {
ret = find_panel_or_bridge(node, panel, bridge);
of_node_put(node);
if (!ret)
return 0;
}
}
/* Otherwise check for any child node other than port/ports. */
for_each_available_child_of_node(np, node) {
if (of_node_name_eq(node, "port") ||
of_node_name_eq(node, "ports"))
continue;
goto of_find_panel_or_bridge;
ret = find_panel_or_bridge(node, panel, bridge);
of_node_put(node);
/* Stop at the first found occurrence. */
if (!ret)
return 0;
}
/*
* of_graph_get_remote_node() produces a noisy error message if port
* node isn't found and the absence of the port is a legit case here,
* so at first we silently check whether graph presents in the
* device-tree node.
*/
if (!of_graph_is_present(np))
return -ENODEV;
remote = of_graph_get_remote_node(np, port, endpoint);
of_find_panel_or_bridge:
if (!remote)
return -ENODEV;
if (panel) {
*panel = of_drm_find_panel(remote);
if (!IS_ERR(*panel))
ret = 0;
else
*panel = NULL;
}
/* No panel found yet, check for a bridge next. */
if (bridge) {
if (ret) {
*bridge = of_drm_find_bridge(remote);
if (*bridge)
ret = 0;
} else {
*bridge = NULL;
}
}
of_node_put(remote);
return ret;
return -EPROBE_DEFER;
}
EXPORT_SYMBOL_GPL(drm_of_find_panel_or_bridge);