From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Pingfan Liu <kernelfans@gmail.com>,
linux-kernel@vger.kernel.org,
Grygorii Strashko <grygorii.strashko@ti.com>,
Christoph Hellwig <hch@infradead.org>,
Bjorn Helgaas <helgaas@kernel.org>,
Dave Young <dyoung@redhat.com>,
linux-pci@vger.kernel.org, Lukas Wunner <lukas@wunner.de>,
Linux PM <linux-pm@vger.kernel.org>
Subject: [PATCH] driver core: Drop devices_kset_move_last() call from really_probe()
Date: Fri, 06 Jul 2018 12:00:06 +0200 [thread overview]
Message-ID: <8816662.k3KXbdkA2e@aspire.rjw.lan> (raw)
In-Reply-To: <CAFgQCTsGC8NH+5kXYD7vykJeUsaAzCAjgxSP-R0EqA3YvgsY0w@mail.gmail.com>
From: Rafael J. Wysocki <rafael.j.wysocki@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_xPAc03SgHjQ@mail.gmail.com/
Reported-by: Pingfan Liu <kernelfans@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@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)
next prev parent reply other threads:[~2018-07-06 10:01 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-03 6:50 [PATCHv3 0/4] drivers/base: bugfix for supplier<-consumer ordering in device_kset Pingfan Liu
2018-07-03 6:50 ` [PATCHv3 1/4] drivers/base: fold the routine of device's shutdown into a func Pingfan Liu
2018-07-03 6:50 ` [PATCHv3 2/4] drivers/base: utilize device tree info to shutdown devices Pingfan Liu
2018-07-03 7:51 ` Lukas Wunner
2018-07-03 9:26 ` Pingfan Liu
2018-07-04 3:10 ` Pingfan Liu
2018-07-03 10:58 ` Andy Shevchenko
2018-07-03 17:03 ` Pavel Tatashin
2018-07-04 17:04 ` kbuild test robot
2018-07-05 10:11 ` Rafael J. Wysocki
2018-07-06 3:02 ` Pingfan Liu
2018-07-06 9:53 ` Rafael J. Wysocki
2018-07-07 4:02 ` Pingfan Liu
2018-07-06 10:00 ` Rafael J. Wysocki [this message]
2018-07-09 13:57 ` [PATCH] driver core: Drop devices_kset_move_last() call from really_probe() Bjorn Helgaas
2018-07-09 21:35 ` Rafael J. Wysocki
2018-07-09 22:06 ` Bjorn Helgaas
2018-07-10 6:19 ` Kishon Vijay Abraham I
2018-07-10 10:32 ` Rafael J. Wysocki
2018-07-10 10:29 ` Rafael J. Wysocki
2018-07-10 6:33 ` Pingfan Liu
2018-07-10 11:35 ` [PATCH] driver core: Partially revert "driver core: correct device's shutdown order" Rafael J. Wysocki
2018-07-10 12:22 ` Kishon Vijay Abraham I
2018-07-10 12:38 ` Rafael J. Wysocki
2018-07-10 12:51 ` [PATCH v2] " Rafael J. Wysocki
2018-07-10 12:59 ` Greg Kroah-Hartman
2018-07-10 15:40 ` Rafael J. Wysocki
2018-07-10 15:47 ` Greg Kroah-Hartman
2018-07-10 19:13 ` Kishon Vijay Abraham I
2018-07-03 6:50 ` [PATCHv3 3/4] drivers/base: clean up the usage of devices_kset_move_last() Pingfan Liu
2018-07-03 14:26 ` Rafael J. Wysocki
2018-07-04 4:40 ` Pingfan Liu
2018-07-04 10:17 ` Rafael J. Wysocki
2018-07-05 2:32 ` Pingfan Liu
2018-07-03 6:50 ` [PATCHv3 4/4] Revert "driver core: correct device's shutdown order" Pingfan Liu
2018-07-03 14:35 ` [PATCHv3 0/4] drivers/base: bugfix for supplier<-consumer ordering in device_kset Rafael J. Wysocki
2018-07-04 2:47 ` Pingfan Liu
2018-07-04 10:21 ` Rafael J. Wysocki
2018-07-05 2:44 ` Pingfan Liu
2018-07-05 9:18 ` Rafael J. Wysocki
2018-07-06 8:36 ` Lukas Wunner
2018-07-06 8:47 ` Rafael J. Wysocki
2018-07-06 13:55 ` Pingfan Liu
2018-07-07 4:24 ` Pingfan Liu
2018-07-08 8:25 ` Rafael J. Wysocki
2018-07-09 6:48 ` Pingfan Liu
2018-07-09 7:48 ` Rafael J. Wysocki
2018-07-09 8:40 ` Pingfan Liu
2018-07-09 8:58 ` Rafael J. Wysocki
2018-07-06 10:02 ` Kishon Vijay Abraham I
2018-07-06 13:52 ` Pingfan Liu
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