From: Arnd Bergmann <arnd@arndb.de>
To: Yijing Wang <wangyijing@huawei.com>
Cc: Liviu Dudau <liviu@dudau.co.uk>, Tony Luck <tony.luck@intel.com>,
Russell King <linux@arm.linux.org.uk>,
linux-pci@vger.kernel.org, x86@kernel.org,
linux-kernel@vger.kernel.org, Xinwei Hu <huxinwei@huawei.com>,
Thierry Reding <thierry.reding@gmail.com>,
Suravee.Suthikulpanit@amd.com,
Bjorn Helgaas <bhelgaas@google.com>,
linux-ia64@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>,
Wuyun <wuyun.wu@huawei.com>,
linuxppc-dev@lists.ozlabs.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [RFC PATCH 07/16] PCI: Separate pci_host_bridge creation out of pci_create_root_bus()
Date: Tue, 18 Nov 2014 13:25:32 +0100 [thread overview]
Message-ID: <2911754.xsk2IUfQFO@wuerfel> (raw)
In-Reply-To: <546B3124.7070206@huawei.com>
On Tuesday 18 November 2014 19:44:36 Yijing Wang wrote:
> On 2014/11/18 17:30, Arnd Bergmann wrote:
> > On Tuesday 18 November 2014 16:32:26 Yijing Wang wrote:
> >
> >>>> +static struct resource busn_resource = {
> >>>> + .name = "PCI busn",
> >>>> + .start = 0,
> >>>> + .end = 255,
> >>>> + .flags = IORESOURCE_BUS,
> >>>> +};
> >>>
> >>> I think it would be better to require callers to pass the bus resource
> >>> down to the function.
> >>
> >> Hmm, I think most of caller will provide the bus resource, but some others
> >> will not give any bus resource, extremely, no any resources :(. But we still
> >> need properly configure their resources for compatibility.
> >
> > I think that is what the conversion to pci_scan_bus_parented() is about:
> > The idea is that we add the correct bus resource to callers of
> > pci_scan_bus_parented or pci_scan_bus and then change them to call
> > pci_scan_root_bus instead.
>
> It looks good to me, but for simplification, or I will try to use a wrapper to
> process the drivers don't pass the busnr resources, and make sure the generic
> pci_create_host_bridge() always get the valid resources.
Ok.
> >>>> +struct pci_host_bridge *pci_create_host_bridge(
> >>>> + struct device *parent, u32 db,
> >>>> + struct pci_ops *ops, void *sysdata,
> >>>> + struct list_head *resources)
> >>>> +{
> >>>
> >>> Do we still need to pass the 'sysdata' in here? If we are guaranteed to
> >>> have a device pointer, we should always be able to get the driver
> >>> private data from dev_get_drvdata(host->dev->parent).
> >>
> >> We need, some platforms pass NULL pointer as host bridge parent.
> >
> > But those don't have to use the new pci_create_host_bridge() function,
> > right?
>
> As I mentioned in another reply, I hope all pci host drivers could use
> pci_create_host_bridge(), keep different PCI scan interfaces in PCI core
> make things become complex.
Doing this for all platforms that have PCI support would be a lot of
work though, I think it's better to focus on having a the best interface
for the majority of users.
Arnd
next prev parent reply other threads:[~2014-11-18 12:26 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-17 10:21 [RFC PATCH 00/16] Refine PCI host bridge scan interfaces Yijing Wang
2014-11-17 10:21 ` [RFC PATCH 01/16] PCI: Enhance pci_scan_root_bus() to support default IO/MEM resources Yijing Wang
2014-11-17 10:08 ` Arnd Bergmann
2014-11-18 7:44 ` Yijing Wang
2014-11-18 9:36 ` Arnd Bergmann
2014-11-18 11:46 ` Yijing Wang
2014-11-18 14:23 ` Liviu Dudau
2014-11-19 1:15 ` Yijing Wang
2014-11-17 10:21 ` [RFC PATCH 02/16] PCI: Use pci_scan_root_bus() instead of pci_scan_bus() Yijing Wang
2014-11-18 14:28 ` Liviu Dudau
2014-11-19 1:19 ` Yijing Wang
2014-11-17 10:21 ` [RFC PATCH 03/16] PCI: Clean up pci_scan_bus() Yijing Wang
2014-11-17 10:21 ` [RFC PATCH 04/16] PCI: Rip out pci_bus_add_devices() from pci_scan_root_bus() Yijing Wang
2014-11-18 14:34 ` Liviu Dudau
2014-11-19 1:21 ` Yijing Wang
2014-11-17 10:21 ` [RFC PATCH 05/16] PCI: Use pci_scan_root_bus() instead of pci_scan_bus_parented() Yijing Wang
2014-11-17 10:21 ` [RFC PATCH 06/16] PCI: Use u32 type to combine PCI domain and bus number Yijing Wang
2014-11-17 10:21 ` [RFC PATCH 07/16] PCI: Separate pci_host_bridge creation out of pci_create_root_bus() Yijing Wang
2014-11-17 10:56 ` Arnd Bergmann
2014-11-18 8:32 ` Yijing Wang
2014-11-18 9:30 ` Arnd Bergmann
2014-11-18 11:44 ` Yijing Wang
2014-11-18 12:25 ` Arnd Bergmann [this message]
2014-11-18 12:41 ` Yijing Wang
2014-11-18 14:48 ` Liviu Dudau
2014-11-19 2:24 ` Yijing Wang
2014-11-19 16:29 ` Liviu Dudau
2014-11-20 2:00 ` Yijing Wang
2014-11-18 15:30 ` Liviu Dudau
2014-11-19 1:42 ` Yijing Wang
2014-11-19 16:37 ` Liviu Dudau
2014-11-20 2:47 ` Yijing Wang
2014-11-20 9:47 ` Liviu Dudau
2014-11-21 2:53 ` Yijing Wang
2014-11-21 9:53 ` Liviu Dudau
2014-11-17 10:21 ` [RFC PATCH 08/16] PCI: Introduce pci_scan_host_bridge() and pci_host_info Yijing Wang
2014-11-18 15:42 ` Liviu Dudau
2014-11-19 2:09 ` Yijing Wang
2014-11-19 16:41 ` Liviu Dudau
2014-11-20 2:54 ` Yijing Wang
2014-11-17 10:21 ` [RFC PATCH 09/16] PCI: Associate .get_msi_ctrl() with pci_host_bridge Yijing Wang
2014-11-17 15:03 ` Lorenzo Pieralisi
2014-11-17 10:21 ` [RFC PATCH 10/16] PCI: Add of_scan_bus() to pci_host_info Yijing Wang
2014-11-17 10:21 ` [RFC PATCH 11/16] x86/PCI: Use pci_scan_host_bridge() instead of pci_create_root_bus() Yijing Wang
2014-11-17 10:21 ` [RFC PATCH 12/16] ia64/PCI: Remove the redundant bus variable Yijing Wang
2014-11-17 10:21 ` [RFC PATCH 13/16] ia64/PCI: Use pci_scan_host_bridge() to refactor pci_acpi_scan_root() Yijing Wang
2014-11-17 10:21 ` [RFC PATCH 14/16] arm/PCI: Introduce pci_get_domain_nr() Yijing Wang
2014-11-17 12:08 ` Lorenzo Pieralisi
2014-11-18 0:55 ` Yijing Wang
2014-11-17 10:21 ` [RFC PATCH 15/16] arm/PCI: Use pci_scan_host_bridge() instead of pci_scan_root_bus() Yijing Wang
2014-11-17 10:21 ` [RFC PATCH 16/16] powerpc/PCI: Use pci_scan_host_bridge() to scan PCI bus Yijing Wang
2014-11-17 14:13 ` [RFC PATCH 00/16] Refine PCI host bridge scan interfaces Arnd Bergmann
2014-11-18 11:17 ` Yijing Wang
2014-11-18 11:30 ` Arnd Bergmann
2014-11-18 11:45 ` Lorenzo Pieralisi
2014-11-18 12:14 ` Yijing Wang
2014-11-18 12:17 ` Yijing Wang
2014-11-18 12:27 ` Arnd Bergmann
2014-11-20 12:01 ` Tomasz Nowicki
2014-11-20 13:15 ` Arnd Bergmann
2014-11-20 11:54 ` Tomasz Nowicki
2014-11-20 12:08 ` Liviu Dudau
2014-11-20 12:53 ` Tomasz Nowicki
2014-11-20 16:39 ` Liviu Dudau
2014-11-21 2:58 ` Yijing Wang
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