@@ -1521,7 +1521,18 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
dev_set_name(&adap->dev, "i2c-%d", adap->nr);
adap->dev.bus = &i2c_bus_type;
adap->dev.type = &i2c_adapter_type;
- res = device_register(&adap->dev);
+ device_initialize(&adap->dev);
+
+ /*
+ * This adapter can be used as a parent immediately after device_add(),
+ * setup runtime-pm (especially ignore-children) before hand.
+ */
+ device_enable_async_suspend(&adap->dev);
+ pm_runtime_no_callbacks(&adap->dev);
+ pm_suspend_ignore_children(&adap->dev, true);
+ pm_runtime_enable(&adap->dev);
+
+ res = device_add(&adap->dev);
if (res) {
pr_err("adapter '%s': can't register device (%d)\n", adap->name, res);
goto out_list;
@@ -1533,11 +1544,6 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
if (res)
goto out_reg;
- device_enable_async_suspend(&adap->dev);
- pm_runtime_no_callbacks(&adap->dev);
- pm_suspend_ignore_children(&adap->dev, true);
- pm_runtime_enable(&adap->dev);
-
res = i2c_init_recovery(adap);
if (res == -EPROBE_DEFER)
goto out_reg;
Platform glue code, which is not build into the kernel and thus cannot use i2c_register_board_info() may want to use bus_register_notifier() to listen for i2c-adapters to show up on which the platform code needs to manually instantiate platform specific i2c_clients. This results in calling i2c_new_client_device() from the bus notifier which happens near the device_add() call. If the i2c-core has not yet setup runtime-pm (specifically the no-callbacks and ignore-children flags) for the device embedded inside struct i2c_adapter and the driver for the i2c_client calls pm_runtime_set_active() this will trigger the following error inside __pm_runtime_set_status(): "runtime PM trying to activate child device %s but parent (%s) is not active\n" and the i2c_client's runtime-status will not be updated. Split the device_register() call for the adapter into device_initialize() and device_add() and move the pm-runtime init calls inbetween these 2 calls so that the runtime-status can be correctly set when a driver binds from the bus-notifier. Note the moved pm-runtime init calls just override the initial value of some flags in struct device set by device_initialize() and calling these before device_add() is safe. Signed-off-by: Hans de Goede <hdegoede@redhat.com> --- Changes in v4: - Add a comment explaining why runtime-pm needs to be setup before the device_add() Changes in v3: - This is a new patch in v3 of this patch-set --- drivers/i2c/i2c-core-base.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-)