Mark (and unmark) device nodes with the POPULATE flag as appropriate.
This is required to avoid multi probing when using I2C and device
overlays containing a mux.
This patch is also more careful with the release of the adapter device
which caused a deadlock with muxes.
Signed-off-by: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
---
drivers/i2c/i2c-core.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 39d25a8..8c32ee3 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -1122,6 +1122,8 @@ EXPORT_SYMBOL_GPL(i2c_new_device);
*/
void i2c_unregister_device(struct i2c_client *client)
{
+ if (client->dev.of_node)
+ of_node_clear_flag(client->dev.of_node, OF_POPULATED);
device_unregister(&client->dev);
}
EXPORT_SYMBOL_GPL(i2c_unregister_device);
@@ -1441,8 +1443,11 @@ static void of_i2c_register_devices(struct i2c_adapter *adap)
dev_dbg(&adap->dev, "of_i2c: walking child nodes\n");
- for_each_available_child_of_node(adap->dev.of_node, node)
+ for_each_available_child_of_node(adap->dev.of_node, node) {
+ if (of_node_test_and_set_flag(node, OF_POPULATED))
+ continue;
of_i2c_register_device(adap, node);
+ }
}
static int of_dev_node_match(struct device *dev, void *data)
@@ -1976,6 +1981,11 @@ static int of_i2c_notify(struct notifier_block *nb, unsigned long action,
if (adap == NULL)
return NOTIFY_OK; /* not for us */
+ if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
+ put_device(&adap->dev);
+ return NOTIFY_OK;
+ }
+
client = of_i2c_register_device(adap, rd->dn);
put_device(&adap->dev);
@@ -1986,6 +1996,10 @@ static int of_i2c_notify(struct notifier_block *nb, unsigned long action,
}
break;
case OF_RECONFIG_CHANGE_REMOVE:
+ /* already depopulated? */
+ if (!of_node_check_flag(rd->dn, OF_POPULATED))
+ return NOTIFY_OK;
+
/* find our device by node */
client = of_find_i2c_device_by_node(rd->dn);
if (client == NULL)
--
1.7.12
--
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