From mboxrd@z Thu Jan 1 00:00:00 1970 From: Darren Hart Subject: Re: [PATCH] ACPI / WMI: Call acpi_wmi_init() later Date: Sat, 6 Jan 2018 14:59:25 -0800 Message-ID: <20180106225925.GA20169@fury> References: <20171208151159.urdcrzl5qpfd6jnu@earth.li> <2601877.IhOx20xkUK@aspire.rjw.lan> <20180106110227.j2jkxjpjktcy6yjr@earth.li> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20180106110227.j2jkxjpjktcy6yjr@earth.li> Sender: platform-driver-x86-owner@vger.kernel.org To: Jonathan McDowell Cc: "Rafael J. Wysocki" , Andy Shevchenko , ACPI Devel Maling List , Linux Kernel Mailing List , Linux Memory Management List , Joonsoo Kim , Platform Driver , Andy Lutomirski List-Id: linux-acpi@vger.kernel.org On Sat, Jan 06, 2018 at 11:02:27AM +0000, Jonathan McDowell wrote: > On Sat, Jan 06, 2018 at 12:30:23AM +0100, Rafael J. Wysocki wrote: > > On Wed, Jan 3, 2018 at 12:49 PM, Rafael J. Wysocki wrote: > > > From: Rafael J. Wysocki > > > > > > Calling acpi_wmi_init() at the subsys_initcall() level causes ordering > > > issues to appear on some systems and they are difficult to reproduce, > > > because there is no guaranteed ordering between subsys_initcall() > > > calls, so they may occur in different orders on different systems. > > > > > > In particular, commit 86d9f48534e8 (mm/slab: fix kmemcg cache > > > creation delayed issue) exposed one of these issues where genl_init() > > > and acpi_wmi_init() are both called at the same initcall level, but > > > the former must run before the latter so as to avoid a NULL pointer > > > dereference. > > > > > > For this reason, move the acpi_wmi_init() invocation to the > > > initcall_sync level which should still be early enough for things > > > to work correctly in the WMI land. > > > > > > Link: https://marc.info/?t=151274596700002&r=1&w=2 > > > Reported-by: Jonathan McDowell > > > Reported-by: Joonsoo Kim > > > Tested-by: Jonathan McDowell > > > Signed-off-by: Rafael J. Wysocki > > > > Guys, this fixes a crash on boot. > > > > If there are no concerns/objections I will just take it through the ACPI tree. > > Note that I first started seeing it in v4.9 so would ideally hit the > appropriate stable trees too. Thanks, I'll take care of that. -- Darren Hart VMware Open Source Technology Center