From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andy Shevchenko <andy.shevchenko@gmail.com>
Subject: Re: [PATCH v13 7/9] ACPI: Translate the I/O range of non-MMIO devices
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Date: Wed, 14 Feb 2018 18:16:53 +0200
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To: John Garry <john.garry@huawei.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>, "Rafael J. Wysocki" <rafael@kernel.org>, Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>, "Rafael J. Wysocki" <rjw@rjwysocki.net>, Hanjun Guo <hanjun.guo@linaro.org>, Rob Herring <robh+dt@kernel.org>, Bjorn Helgaas <bhelgaas@google.com>, Arnd Bergmann <arnd@arndb.de>, Mark Rutland <mark.rutland@arm.com>, Olof Johansson <olof@lixom.net>, Dann Frazier <dann.frazier@canonical.com>, Rob Herring <robh@kernel.org>, Joe Perches <joe@perches.com>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, linux-pci@vger.kernel.org, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, ACPI Devel Maling List <linux-acpi@vger.kernel.org>, Linuxarm <linuxarm@huawei.com>, Corey Minyard <minyard@acm.org>devicetree <d>
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On Wed, Feb 14, 2018 at 5:33 PM, John Garry <john.garry@huawei.com> wrote:
> On 14/02/2018 13:53, Andy Shevchenko wrote:
>> On Tue, Feb 13, 2018 at 7:45 PM, John Garry <john.garry@huawei.com> wrote:

>>> +       sys_port = logic_pio_trans_hwaddr(&host->fwnode, res->start,
>>> len);
>>> +       if (sys_port == -1UL)

>> Wouldn't it be better to compare with ULONG_MAX?

> Could do, being the same thing. Maybe people prefer -1UL as it saves having
> to figure out what ULONG_MAX is :)

-1UL looks confusing.

Another approach is to use ~0UL if that is preferable.

>>> +       list_for_each_entry(rentry, &resource_list, node)
>>> +               resources[count++] = *rentry->res;

>> It has similarities with acpi_create_platform_device().
>> I guess we can utilize existing code.

> For sure, this particular segment is effectively same as part of
> acpi_create_platform_device():

Not the same, acpi_create_platform_device() does a bit more than
copying the resources. If it indeed makes no hurt...

>         list_for_each_entry(rentry, &resource_list, node)
>             acpi_platform_fill_resource(adev, rentry->res,
>                             &resources[count++]);

> So is your idea to refactor this common segment into a helper function?

...I would go with helper.

>>> +               char *name = &acpi_indirect_io_mfd_cell[count].name[0];
>>> +               char *pnpid = &acpi_indirect_io_mfd_cell[count].pnpid[0];
>>
>>
>> Plain x is equivalent to &x[0].

> Right, but I thought for arrays that we should use address of x rather than
> x itself, no?

x is addressed by it's beginning.

-- 
With Best Regards,
Andy Shevchenko