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Date: Mon, 27 Sep 2021 23:48:30 +0300
From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To: Rob Herring <robh+dt@...nel.org>,
Frank Rowand <frowand.list@...il.com>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
Saravana Kannan <saravanak@...gle.com>
Subject: [PATCH] Revert "of: property: fw_devlink: Add support for remote-endpoint"
Since the commit f7514a663016 ("of: property: fw_devlink: Add support
for remote-endpoint") Linux kernel started parsing and adding devlinks
for the remote-endpoint properties. However this brings more harm than
good.
For all the remote-endpoints in the graph two links are created. Thus
each and every remote-endpoint ends up in the cyclic graph (instead of
the original intent of catching a cycle of graph + non-graph link):
[ 0.381057] OF: remote-endpoint linking /soc@...eniqup@...000/i2c@...000/hdmi-bridge@2b to /soc@...dss@...0000/dsi@...4000/ports/port@...ndpoint
[ 0.394421] OF: remote-endpoint linking /soc@...eniqup@...000/i2c@...000/hdmi-bridge@2b to /hdmi-out/port/endpoint
[ 0.407007] OF: remote-endpoint linking /soc@...hy@...9000 to /soc@...pmi@...0000/pmic@...mic-tcpm/connector/ports/port@...ndpoint@0
[ 0.419648] OF: remote-endpoint linking /soc@...sb@...8800/usb@...0000 to /soc@...pmi@...0000/pmic@...mic-tcpm/ports/port@...ndpoint@0
[ 0.432578] OF: remote-endpoint linking /soc@...ci@...f000/i2c-bus@...am1@c0 to /soc@...amss@...a000/ports/port@...ndpoint
[ 0.444450] OF: remote-endpoint linking /soc@...amss@...a000 to /soc@...ci@...f000/i2c-bus@...am1@...port/endpoint
[ 0.455292] OF: remote-endpoint linking /soc@...dss@...0000/mdp@...1000 to /soc@...dss@...0000/dsi@...4000/ports/port@...ndpoint
[ 0.467210] OF: remote-endpoint linking /soc@...dss@...0000/mdp@...1000 to /soc@...dss@...0000/dsi@...6000/ports/port@...ndpoint
[ 0.479239] OF: remote-endpoint linking /soc@...dss@...0000/dsi@...4000 to /soc@...dss@...0000/mdp@...1000/ports/port@...ndpoint
[ 0.491147] OF: remote-endpoint linking /soc@...dss@...0000/dsi@...4000 to /soc@...eniqup@...000/i2c@...000/hdmi-bridge@...ports/port@...ndpoint
[ 0.504979] OF: remote-endpoint linking /soc@...pmi@...0000/pmic@...ypec@...0 to /soc@...pmi@...0000/pmic@...mic-tcpm/ports/port@...ndpoint
[ 0.517958] OF: remote-endpoint linking /soc@...pmi@...0000/pmic@...dphy@...0 to /soc@...pmi@...0000/pmic@...mic-tcpm/ports/port@...ndpoint
[ 0.565326] OF: remote-endpoint linking /hdmi-out to /soc@...eniqup@...000/i2c@...000/hdmi-bridge@...ports/port@...ndpoint
Under some conditions the device can become it's own supplier,
preventing this device to be probed at all:
$ ls -l /sys/bus/platform/devices/ae00000.mdss/
lrwxrwxrwx 1 root root 0 Aug 4 15:13 consumer:platform:ae00000.mdss -> ../../../virtual/devlink/platform:ae00000.mdss--platform:ae00000.mdss
I think that until of_link can be tought to handle bi-directional links
on its own, we should not parse remote-endpoint properties. Thus the
aforementioned commit should be reverted.
Cc: Saravana Kannan <saravanak@...gle.com>
Fixes: f7514a663016 ("of: property: fw_devlink: Add support for remote-endpoint")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
---
drivers/of/property.c | 47 +++++++++++++++----------------------------
1 file changed, 16 insertions(+), 31 deletions(-)
diff --git a/drivers/of/property.c b/drivers/of/property.c
index a3483484a5a2..6aaaf01ef36e 100644
--- a/drivers/of/property.c
+++ b/drivers/of/property.c
@@ -1056,25 +1056,6 @@ static bool of_is_ancestor_of(struct device_node *test_ancestor,
return false;
}
-static struct device_node *of_get_compat_node(struct device_node *np)
-{
- of_node_get(np);
-
- while (np) {
- if (!of_device_is_available(np)) {
- of_node_put(np);
- np = NULL;
- }
-
- if (of_find_property(np, "compatible", NULL))
- break;
-
- np = of_get_next_parent(np);
- }
-
- return np;
-}
-
/**
* of_link_to_phandle - Add fwnode link to supplier from supplier phandle
* @con_np: consumer device tree node
@@ -1098,11 +1079,25 @@ static int of_link_to_phandle(struct device_node *con_np,
struct device *sup_dev;
struct device_node *tmp_np = sup_np;
+ of_node_get(sup_np);
/*
* Find the device node that contains the supplier phandle. It may be
* @sup_np or it may be an ancestor of @sup_np.
*/
- sup_np = of_get_compat_node(sup_np);
+ while (sup_np) {
+
+ /* Don't allow linking to a disabled supplier */
+ if (!of_device_is_available(sup_np)) {
+ of_node_put(sup_np);
+ sup_np = NULL;
+ }
+
+ if (of_find_property(sup_np, "compatible", NULL))
+ break;
+
+ sup_np = of_get_next_parent(sup_np);
+ }
+
if (!sup_np) {
pr_debug("Not linking %pOFP to %pOFP - No device\n",
con_np, tmp_np);
@@ -1249,7 +1244,6 @@ static struct device_node *parse_##fname(struct device_node *np, \
* @parse_prop.index: For properties holding a list of phandles, this is the
* index into the list
* @optional: Describes whether a supplier is mandatory or not
- * @node_not_dev: The consumer node containing the property is never a device.
*
* Returns:
* parse_prop() return values are
@@ -1261,7 +1255,6 @@ struct supplier_bindings {
struct device_node *(*parse_prop)(struct device_node *np,
const char *prop_name, int index);
bool optional;
- bool node_not_dev;
};
DEFINE_SIMPLE_PROP(clocks, "clocks", "#clock-cells")
@@ -1286,7 +1279,6 @@ DEFINE_SIMPLE_PROP(pinctrl5, "pinctrl-5", NULL)
DEFINE_SIMPLE_PROP(pinctrl6, "pinctrl-6", NULL)
DEFINE_SIMPLE_PROP(pinctrl7, "pinctrl-7", NULL)
DEFINE_SIMPLE_PROP(pinctrl8, "pinctrl-8", NULL)
-DEFINE_SIMPLE_PROP(remote_endpoint, "remote-endpoint", NULL)
DEFINE_SIMPLE_PROP(pwms, "pwms", "#pwm-cells")
DEFINE_SIMPLE_PROP(resets, "resets", "#reset-cells")
DEFINE_SIMPLE_PROP(leds, "leds", NULL)
@@ -1374,7 +1366,6 @@ static const struct supplier_bindings of_supplier_bindings[] = {
{ .parse_prop = parse_pinctrl6, },
{ .parse_prop = parse_pinctrl7, },
{ .parse_prop = parse_pinctrl8, },
- { .parse_prop = parse_remote_endpoint, .node_not_dev = true, },
{ .parse_prop = parse_pwms, },
{ .parse_prop = parse_resets, },
{ .parse_prop = parse_leds, },
@@ -1421,16 +1412,10 @@ static int of_link_property(struct device_node *con_np, const char *prop_name)
}
while ((phandle = s->parse_prop(con_np, prop_name, i))) {
- struct device_node *con_dev_np;
-
- con_dev_np = s->node_not_dev
- ? of_get_compat_node(con_np)
- : of_node_get(con_np);
matched = true;
i++;
- of_link_to_phandle(con_dev_np, phandle);
+ of_link_to_phandle(con_np, phandle);
of_node_put(phandle);
- of_node_put(con_dev_np);
}
s++;
}
--
2.33.0
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