This is a note to let you know that I've just added the patch titled PM: runtime: Resume the device earlier in __device_release_driver() to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: pm-runtime-resume-the-device-earlier-in-__device_release_driver.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 9226c504e364158a17a68ff1fe9d67d266922f50 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx> Date: Thu, 22 Oct 2020 17:38:22 +0200 Subject: PM: runtime: Resume the device earlier in __device_release_driver() From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> 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@xxxxxxxxx> Fixes: 9ed9895370ae ("driver core: Functional dependencies tracking support") Cc: All applicable <stable@xxxxxxxxxxxxxxx> # All applicable Tested-by: Xiang Chen <chenxiang66@xxxxxxxxxxxxx> Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/base/dd.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- 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); Patches currently in stable-queue which might be from rafael.j.wysocki@xxxxxxxxx are queue-4.19/acpi-nfit-fix-comparison-to-enxio.patch queue-4.19/pm-runtime-resume-the-device-earlier-in-__device_release_driver.patch