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Message-ID: <5b7024af-33c8-48c8-22bc-8d36ca3eadd8@huawei.com>
Date: Fri, 2 Mar 2018 10:48:21 +0000
From: John Garry <john.garry@...wei.com>
To: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
<mika.westerberg@...ux.intel.com>, <rafael@...nel.org>,
<lorenzo.pieralisi@....com>, <rjw@...ysocki.net>,
<hanjun.guo@...aro.org>, <robh+dt@...nel.org>,
<bhelgaas@...gle.com>, <arnd@...db.de>, <mark.rutland@....com>,
<olof@...om.net>, <dann.frazier@...onical.com>,
<andy.shevchenko@...il.com>, <robh@...nel.org>
CC: <joe@...ches.com>, <benh@...nel.crashing.org>,
<linux-pci@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<linux-acpi@...r.kernel.org>, <linuxarm@...wei.com>,
<minyard@....org>, <devicetree@...r.kernel.org>,
<linux-arch@...r.kernel.org>, <rdunlap@...radead.org>,
<gregkh@...uxfoundation.org>, <akpm@...ux-foundation.org>,
<frowand.list@...il.com>, <agraf@...e.de>
Subject: Re: [PATCH v15 0/9] LPC: legacy ISA I/O support
On 01/03/2018 19:52, Andy Shevchenko wrote:
> On Tue, 2018-02-27 at 00:40 +0800, John Garry wrote:
>> > This patchset supports the IPMI-bt device attached to the Low-Pin-
>> > Count
>> > interface implemented on Hisilicon Hip06/Hip07 SoC.
>> > -----------
>> > | LPC host|
>> > | |
>> > -----------
>> > |
>> > _____________V_______________LPC
>> > | |
>> > V V
>> > ------------
>> > | BT(ipmi)|
>> > ------------
>> >
>> > When master accesses those peripherals beneath the Hip06/Hip07 LPC, a
>> > specific
>> > LPC driver is needed to make LPC host generate the standard LPC I/O
>> > cycles with
>> > the target peripherals'I/O port addresses. But on curent arm64 world,
>> > there is
>> > no real I/O accesses. All the I/O operations through in/out accessors
>> > are based
>> > on MMIO ranges; on Hip06/Hip07 LPC the I/O accesses are performed
>> > through driver
>> > specific accessors rather than MMIO.
>> > To solve this issue and keep the relevant existing peripherals'
>> > drivers untouched,
>> > this patchset:
>> > - introduces a generic I/O space management framework, logical PIO,
>> > to support
>> > I/O operations on host controllers operating either on MMIO
>> > buses or on buses
>> > requiring specific driver I/O accessors;
>> > - redefines the in/out accessors to provide a unified interface for
>> > both MMIO
>> > and driver specific I/O operations. Using logical PIO, th call of
>> > in/out() from
>> > the host children drivers, such as ipmi-si, will be redirected to
>> > the
>> > corresponding device-specific I/O hooks to perform the I/O
>> > accesses.
>> >
>> > Based on this patch-set, all the I/O accesses to Hip06/Hip07 LPC
>> > peripherals can
>> > be supported without any changes on the existing ipmi-si driver.
>> >
>> > The whole patchset has been tested on Hip07 D05 board both using DTB
>> > and ACPI.
>> >
> I did a review and don't see the patch 8 is ready to go.
>
> So, to move things forward I may suggest to reorder series that some
> small preparation stuff can go first w/o dependency to the actual Logic
> PIO / LPC.
>
Hi Andy,
As mentioned in the reply to patch #8, as a practical exercise I don't
see the reason to change it now. Let's conclude that issue first before
deciding on patchset revising.
Thanks very much,
John
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