From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Garry Subject: Re: [PATCH v12 7/9] ACPI: Translate the I/O range of non-MMIO devices before scanning Date: Mon, 5 Feb 2018 14:25:20 +0000 Message-ID: <62634aa6-ad3c-93c2-e6fa-9e163d4004ca@huawei.com> References: <1516725385-24535-1-git-send-email-john.garry@huawei.com> <1516725385-24535-8-git-send-email-john.garry@huawei.com> <0a30452f-34eb-d0b5-2001-ab6b866c53e2@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-pci-owner@vger.kernel.org To: Andy Shevchenko Cc: Mika Westerberg , "Rafael J. Wysocki" , Lorenzo Pieralisi , "Rafael J. Wysocki" , Rob Herring , Bjorn Helgaas , Arnd Bergmann , Mark Rutland , Olof Johansson , Hanjun Guo , dann.frazier@canonical.com, Benjamin Herrenschmidt , Linux Kernel Mailing List , ACPI Devel Maling List , Linuxarm , linux-pci@vger.kernel.org, Corey Minyard , devicetree , Linux-Arch List-Id: devicetree@vger.kernel.org On 05/02/2018 13:16, Andy Shevchenko wrote: > On Thu, Feb 1, 2018 at 1:32 PM, John Garry wrote: > > Hi Andy, > I'm not going through all patch, by one thing I would like you to pay > attention on, i.e. > printing resource_size_t and struct resource > >>> + dev_err(dev, "translate bus-addr(0x%llx) fail!\n", >>> + resource->start); > > resource_size_t is dynamic width type, you will see a compiler > warning. For this we have > %pap specifier. > > Moreover, in some cases it's useful to print struct resource via %pR or %pr. I have already fixed this up in my rework. > > Consider reading kernel documentation about these (printk-formats.rst). > >>> +struct acpi_indirectio_host_data { >>> + resource_size_t io_size; >>> + resource_size_t io_start; >>> +}; > > Why not utilize struct resource? > > If it's coming from platform / firmware it should *never* have types > like size_t, unsigned long, resource_size_t, etc. This is not coming from firmware, but it is a struct which we define in the kernel per host, describing that host bus address range for translation. In fact, generally io_start is 0 and the io_size would be PIO_INDIRECT_SIZE, so I'll consider removing it for now. > >>> +/* All the host devices which apply indirect-IO can be listed here. */ >>> +static const struct acpi_device_id acpi_indirect_host_id[] = { >>> + {""}, >>> +}; > > The idea of terminator is to be such (remove comma there). And it's > basically redundant to have an empty string there. Moreover, it's a > waste of resources in ro section. OK, the comma should be removed. So what is the preferred acpi device id array sentinel? I see {}, {"", 0}, and {""} used. > thank you, John