From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Commit 52cdbdd49853 (driver core: correct device's shutdown order) introduced a regression by breaking device shutdown on some systems. Namely, the devices_kset_move_last() call in really_probe() added by that commit is a mistake as it may cause parents to follow children in the devices_kset list which then causes shutdown to fail. For example, 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 any more. 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 and it only covers an issue with system shutdown, while system-wide suspend/resume potentially has the same issue on the affected platforms (which is not covered). For that reason, revert the really_probe() modifications made by commit 52cdbdd49853 which unfortunately will expose the shutdown issue the problematic commit attempted to fix (and which will have to be addressed differently and correctly in the future). The other code changes made by commit 52cdbdd49853 are useful and they need not be reverted. Fixes: 52cdbdd49853 (driver core: correct device's shutdown order) Link: https://lore.kernel.org/lkml/CAFgQCTt7VfqM=UyCnvNFxrSw8Z6cUtAi3HUwR4_xPAc03SgHjQ@xxxxxxxxxxxxxx/ Reported-by: Pingfan Liu <kernelfans@xxxxxxxxx> Tested-by: Pingfan Liu <kernelfans@xxxxxxxxx> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> --- This is a v2 of https://patchwork.kernel.org/patch/10511241/ under a different subject. The patch itself hasn't changed, but I rewrote the changelog (as per the Bjorn's request) and changed the subject accordingly. --- 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)
