i2c: enable i2c adapter to suspend/resume asynchronously

Now, PM core supports asynchronous suspend/resume mode for devices during system suspend/resume, and the power state transition of one device may be completed in separate kernel thread. PM core ensures all power state transition timing dependency between devices. This patch enables i2c adapter to suspend/resume asynchronously. This will take advantage of multicore and improve system suspend/resume speed.

Signed-off-by Zhonghui Fu <[email protected]>

---
Changes in v2:
- Amend commit message.

 drivers/i2c/i2c-core.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

drivers/i2c/i2c-core.c +2 -1

index 5f89f1e..c273b55 100644
@@ -1528,6 +1528,8 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
 
 	pm_runtime_no_callbacks(&adap->dev);
 
+	device_enable_async_suspend(&adap->dev);
+
 #ifdef CONFIG_I2C_COMPAT
 	res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev,
 				       adap->dev.parent);
-- 1.7.1