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, and does not break the build
on !OF since the node flag accessors are not defined then.

Signed-off-by: Pantelis Antoniou <pantelis.anton...@konsulko.com>
---
 drivers/i2c/i2c-core.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 39d25a8..1d44e3a 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -1122,6 +1122,10 @@ EXPORT_SYMBOL_GPL(i2c_new_device);
  */
 void i2c_unregister_device(struct i2c_client *client)
 {
+#if IS_ENABLED(CONFIG_OF_DYNAMIC)
+       if (client->dev.of_node)
+               of_node_clear_flag(client->dev.of_node, OF_POPULATED);
+#endif
        device_unregister(&client->dev);
 }
 EXPORT_SYMBOL_GPL(i2c_unregister_device);
@@ -1441,8 +1445,11 @@ 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 +1983,11 @@ 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 +1998,10 @@ 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

--
To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to