Re: [PATCH rev.2 0/6] ACPI: Change the ACPI namespace scanning code ordering

From: "Rafael J. Wysocki" <rjw@sisk.pl>
To: Yijing Wang <wangyijing@huawei.com>
Cc: ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
	Bjorn Helgaas <bhelgaas@google.com>,
	LKML <linux-kernel@vger.kernel.org>,
	linux-pci@vger.kernel.org, Yinghai Lu <yinghai@kernel.org>,
	Toshi Kani <toshi.kani@hp.com>,
	Myron Stowe <myron.stowe@redhat.com>,
	Yijing Wang <wangyijing0307@gmail.com>,
	Jiang Liu <liuj97@gmail.com>
Subject: Re: [PATCH rev.2 0/6] ACPI: Change the ACPI namespace scanning code ordering
Date: Fri, 14 Dec 2012 23:59:36 +0100	[thread overview]
Message-ID: <2226860.gdCKHUSrjo@vostro.rjw.lan> (raw)
In-Reply-To: <50CAF7DE.8000203@huawei.com>

On Friday, December 14, 2012 05:56:46 PM Yijing Wang wrote:
> On 2012/12/14 6:15, Rafael J. Wysocki wrote:
> > Hi All,
> > 
> > On Sunday, December 09, 2012 11:58:42 PM Rafael J. Wysocki wrote:
> >> Hi,
> >>
> >> The following patches change the ordering of the ACPI namespace scanning code
> >> so that all struct acpi_device objects in the given scope are registered before
> >> ACPI drivers are probed against them.  They also do some simplifications and
> >> clarifications of the code made possible by this main change.
> >>
> >> This is done for three basic reasons.  First, we need the boot ACPI namespace
> >> scanning code to be as similar as reasonably possible to the hot-plug ACPI
> >> namespace scanning code.  Second, the ordering of PCI devices enumeration
> >> versus ACPI-backed platform devices registration needs to be such that the PCI
> >> devices in the given scope are all registered first.  Finally, when we start to
> >> actually manage ACPI device resources as appropriate (e.g. resolve resource
> >> conflicts properly) we'll need all struct acpi_device nodes to be registered
> >> before any "companion" physical nodes or ACPI drivers are bound to them.
> >>
> >> The patches have been tested on Toshiba Portege R500 without breaking stuff
> >> (I used some additional debug code to verify that the ordering of device
> >> discovery had not been modified by them), but if you see any problems with
> >> them regarding hot-plug, please let me know.
> >>
> >> [1/6] - Separate adding ACPI device objects from probing ACPI drivers.
> >> [2/6] - Change the ordering of PCI root bridge driver registration.
> >> [3/6] - Make acpi_bus_add() and acpi_bus_start() visibly different.
> >> [4/6] - Reduce the usage of struct acpi_bus_ops
> >> [5/6] - Replace struct acpi_bus_ops with an enum type
> >> [6/6] - Change the ordering of acpi_bus_check_add() to avoid unnecessary checks.
> > 
> > The second revision is necessary to address problems found by Yijing Wang
> > during testing and explained by Jiang Liu (thanks guys!).
> > 
> > The problem is that acpi_walk_namespace() doesn't execute the pre_order_visit
> > callback for the starting handle, so the callback routine has the be executed
> > for it directly, if necessary.
> > 
> > I also modified a couple of changelogs to better explain the motivation of the
> > patches.
> > 
> > Boot sequence tested on Toshiba Portege R500, but testing on systems with
> > hotplug will be appreciated.
> 
> Hi rafael,
>    I tested this version patchset in my ia64 hotplug machine, and the result looks ok.

Great, thanks a lot for testing!

Rafael

-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.