diff mbox series

[4.19,67/71] PM: runtime: Resume the device earlier in __device_release_driver()

Message ID 20201109125023.047558144@linuxfoundation.org
State New
Headers show
Series None | expand

Commit Message

Greg KH Nov. 9, 2020, 12:56 p.m. UTC 
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

commit 9226c504e364158a17a68ff1fe9d67d266922f50 upstream.

Since the device is resumed from runtime-suspend in
__device_release_driver() anyway, it is better to do that before
looking for busy managed device links from it to consumers, because
if there are any, device_links_unbind_consumers() will be called
and it will cause the consumer devices' drivers to unbind, so the
consumer devices will be runtime-resumed.  In turn, resuming each
consumer device will cause the supplier to be resumed and when the
runtime PM references from the given consumer to it are dropped, it
may be suspended.  Then, the runtime-resume of the next consumer
will cause the supplier to resume again and so on.

Update the code accordingly.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Fixes: 9ed9895370ae ("driver core: Functional dependencies tracking support")
Cc: All applicable <stable@vger.kernel.org> # All applicable
Tested-by: Xiang Chen <chenxiang66@hisilicon.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/base/dd.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
diff mbox series

Patch

--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -931,6 +931,8 @@  static void __device_release_driver(stru
 
 	drv = dev->driver;
 	if (drv) {
+		pm_runtime_get_sync(dev);
+
 		while (device_links_busy(dev)) {
 			device_unlock(dev);
 			if (parent && dev->bus->need_parent_lock)
@@ -946,11 +948,12 @@  static void __device_release_driver(stru
 			 * have released the driver successfully while this one
 			 * was waiting, so check for that.
 			 */
-			if (dev->driver != drv)
+			if (dev->driver != drv) {
+				pm_runtime_put(dev);
 				return;
+			}
 		}
 
-		pm_runtime_get_sync(dev);
 		pm_runtime_clean_up_links(dev);
 
 		driver_sysfs_remove(dev);