Re: [PATCH v17 08/10] ACPI / scan: do not enumerate Indirect IO host children

From: John Garry <john.garry@huawei.com>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: mika.westerberg@linux.intel.com, rafael@kernel.org,
	lorenzo.pieralisi@arm.com, hanjun.guo@linaro.org,
	robh+dt@kernel.org, bhelgaas@google.com, arnd@arndb.de,
	mark.rutland@arm.com, olof@lixom.net, dann.frazier@canonical.com,
	andy.shevchenko@gmail.com, robh@kernel.org,
	andriy.shevchenko@linux.intel.com, joe@perches.com,
	benh@kernel.crashing.org, linux-pci@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org,
	linuxarm@huawei.com, minyard@acm.org, devicetree@vger.kernel.org,
	linux-arch@vger.kernel.org, rdunlap@infradead.org,
	gregkh@linuxfoundation.org, akpm@linux-foundation.org,
	frowand.list@gmail.com, agraf@suse.de
Subject: Re: [PATCH v17 08/10] ACPI / scan: do not enumerate Indirect IO host children
Date: Mon, 19 Mar 2018 10:48:34 +0000	[thread overview]
Message-ID: <906b3868-39a5-3807-23a4-dfc52c2e82c4@huawei.com> (raw)
In-Reply-To: <2309217.pWfZsU88YQ@aspire.rjw.lan>

On 19/03/2018 10:30, Rafael J. Wysocki wrote:
> On Wednesday, March 14, 2018 7:15:57 PM CET John Garry wrote:
>> > Through the logical PIO framework systems which otherwise have
>> > no IO space access to legacy ISA/LPC devices may access these
>> > devices through so-called "indirect IO" method. In this, IO
>> > space accesses for non-PCI hosts are redirected to a host
>> > LLDD to manually generate the IO space (bus) accesses. Hosts
>> > are able to register a region in logical PIO space to map to
>> > its bus address range.
>> >
>> > Indirect IO child devices have an associated host-specific bus
>> > address. Special translation is required to map between
>> > a logical PIO address for a device and it's host bus address.
>> >
>> > Since in the ACPI tables the child device IO resources would
>> > be the host-specific values, it is required the ACPI scan code
>> > should not enumerate these devices, and that this should be
>> > the responsibility of the host driver so that it can "fixup"
>> > the resources so that they map to the appropriate logical PIO
>> > addresses.
>> >
>> > To avoid enumerating these child devices, we add a check from
>> > acpi_device_enumeration_by_parent() as to whether the parent
>> > for a device is a member of a known list of "indirect IO" hosts.
>> > For now, the HiSilicon LPC host controller ID is added.
>> >
>> > Signed-off-by: John Garry <john.garry@huawei.com>
>> > Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> You have my ACK here already.
>
> Since I've ACKed the [7/10] too, I don't think there's anything more I can do
> about this series and I'm assuming that it will be routed through other trees.
>
> Thanks!
>

Hi Rafael,

Thanks for this.

Yes, I am working on getting this whole series routed through another 
tree. Actually I think 7+8 could go separately since there is no build 
dependency, but I will try to keep the series together.

All the best, And thanks again,
John