On Fri, Jul 6, 2018 at 6:01 PM Rafael J. Wysocki <r...@rjwysocki.net> wrote:
>
> From: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
>
> The devices_kset_move_last() call in really_probe() is a mistake
> as it may cause parents to follow children in the devices_kset list
> which then causes system shutdown to fail. Namely, if a device has
> children before really_probe() is called for it (which is not
> uncommon), that call will cause it to be reordered after the children
> in the devices_kset list and the ordering of that list will not
> reflect the correct device shutdown order.
>
> Also it causes the devices_kset list to be constantly reordered
> until all drivers have been probed which is totally pointless
> overhead in the majority of cases.
>
> For that reason, revert the really_probe() modifications made by
> commit 52cdbdd49853.
>
> Fixes: 52cdbdd49853 (driver core: correct device's shutdown order)
> Link:
> https://lore.kernel.org/lkml/CAFgQCTt7VfqM=uycnvnfxrsw8z6cutai3huwr4_xpac03sg...@mail.gmail.com/
> Reported-by: Pingfan Liu <kernelf...@gmail.com>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
> ---
> drivers/base/dd.c | 8 --------
> 1 file changed, 8 deletions(-)
>
> Index: linux-pm/drivers/base/dd.c
> ===================================================================
> --- linux-pm.orig/drivers/base/dd.c
> +++ linux-pm/drivers/base/dd.c
> @@ -434,14 +434,6 @@ re_probe:
> goto probe_failed;
> }
>
> - /*
> - * Ensure devices are listed in devices_kset in correct order
> - * It's important to move Dev to the end of devices_kset before
> - * calling .probe, because it could be recursive and parent Dev
> - * should always go first
> - */
> - devices_kset_move_last(dev);
> -
> if (dev->bus->probe) {
> ret = dev->bus->probe(dev);
> if (ret)
>
Tested-by: Pingfan Liu <kernelf...@gmail.com>
