From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Yinghai Lu <yinghai@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>, linux-pci@vger.kernel.org
Subject: Re: [PATCH 01/10] device: add drivers_autoprobe in struct device
Date: Tue, 2 Oct 2012 13:45:48 -0700 [thread overview]
Message-ID: <20121002204548.GC28663@kroah.com> (raw)
In-Reply-To: <CAE9FiQXM6Cy64ZbXtjsnQaMFJi0C1QABC7TNYSBZ3FGsjC8D8w@mail.gmail.com>
On Tue, Oct 02, 2012 at 01:20:58PM -0700, Yinghai Lu wrote:
> On Tue, Oct 2, 2012 at 10:47 AM, Greg Kroah-Hartman
> <gregkh@linuxfoundation.org> wrote:
> > On Tue, Oct 02, 2012 at 10:39:25AM -0700, Yinghai Lu wrote:
> >> On Tue, Oct 2, 2012 at 6:33 AM, Greg Kroah-Hartman
> >> Those patches address Bjorn's request:
> >> 1. kill acpi_pci_root_start in drivers/acpi/pci_root.c
> >> 2. register pci device to device as soon as possible, so for_each_pci_device
> >> could be used early before pci_bus_add_devices.
> >>
> >> please check change log patch2-4.
> >
> > Sorry, I still don't see what is so special about PCI that they have to
> > do something different here. What am I missing?
>
> That is something that core related with hotplug:
>
> for booting and hotplug, we have different code path.
> 1. for booting, all device are enumerated and registered, and later
> driver get registered, driver is attached to the devices.
> 2. for hotplug, one device on the bus is found, and then registered
> and driver is attached, after that
> another device on the bus is found, and then
> registered and driver is attached...
>
> The reason for the difference, device driver is not registered later
> during booting path.
But on each case, the code path in the driver core is the same, and you
don't know if for 1) a driver is not already registered in the system
(think drivers built into the kernel).
> We should make the two path have same sequence. the solution that I
> suggest is adding per device drivers_autoprobe.
No, now you have 2 code paths in the driver core, do not do that.
> and thanking for bus_type notifier that we could toggle that bit
> during device_add, so could make all device on same
> bus get probed and registered but driver get skipped. and after that
> call device_attach for all device at one batch.
>
> That will remove those hotplug related hacks like acpi_pci_root_start
> that try to delay registering of pci devices.
> and make the code lesser and readable.
I don't know what you are doing in the acpi code, but I do not think it
requires a driver core change like this.
Again, why is PCI different from any other bus type? (hint, it
shouldn't be...)
greg k-h
next prev parent reply other threads:[~2012-10-02 20:45 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-02 6:32 [PATCH 00/10] PCI, ACPI: Use bus type notifier for root bus hotplug Yinghai Lu
2012-10-02 6:32 ` [PATCH 01/10] device: add drivers_autoprobe in struct device Yinghai Lu
2012-10-02 13:33 ` Greg Kroah-Hartman
2012-10-02 17:39 ` Yinghai Lu
2012-10-02 17:47 ` Greg Kroah-Hartman
2012-10-02 18:00 ` Bjorn Helgaas
2012-10-02 20:20 ` Yinghai Lu
2012-10-02 20:45 ` Greg Kroah-Hartman [this message]
2012-10-02 21:47 ` Yinghai Lu
2012-10-02 22:38 ` Bjorn Helgaas
2012-10-02 23:20 ` Yinghai Lu
2012-10-03 0:00 ` Yinghai Lu
2012-10-03 2:07 ` Yinghai Lu
2012-10-03 2:08 ` Yinghai Lu
2012-10-03 19:48 ` Bjorn Helgaas
2012-10-03 20:50 ` Yinghai Lu
2012-10-03 23:00 ` [PATCH 0/4] ACPI: kill acpi_pci_root_start Yinghai Lu
2012-10-03 23:00 ` [PATCH 1/4] ACPI: add drivers_autoprobe in struct acpi_device Yinghai Lu
2012-10-04 13:03 ` Konrad Rzeszutek Wilk
2012-10-04 15:15 ` Yinghai Lu
2012-10-09 16:38 ` Konrad Rzeszutek Wilk
2012-10-03 23:00 ` [PATCH 2/4] ACPI: use device drivers_autoprobe to delay loading acpi drivers Yinghai Lu
2012-10-03 23:00 ` [PATCH 3/4] PCI, ACPI: Remove not used acpi_pci_root_start() Yinghai Lu
2012-10-03 23:00 ` [PATCH 4/4] ACPI: remove acpi_op_start workaround Yinghai Lu
2012-10-04 12:57 ` Konrad Rzeszutek Wilk
2012-10-04 17:47 ` [PATCH 0/4] ACPI: kill acpi_pci_root_start Bjorn Helgaas
2012-10-04 18:36 ` Yinghai Lu
2012-10-04 19:44 ` Bjorn Helgaas
2012-10-04 19:54 ` Rafael J. Wysocki
2012-10-04 20:14 ` Yinghai Lu
2012-10-04 20:47 ` Bjorn Helgaas
2012-10-04 19:53 ` Rafael J. Wysocki
2012-10-04 21:23 ` Rafael J. Wysocki
2012-10-04 21:31 ` Yinghai Lu
2012-10-04 21:53 ` Rafael J. Wysocki
2012-10-04 22:01 ` Yinghai Lu
2012-10-04 22:36 ` Rafael J. Wysocki
2012-10-04 22:46 ` Yinghai Lu
2012-10-05 23:01 ` Rafael J. Wysocki
2012-10-05 23:10 ` Yinghai Lu
2012-10-08 20:12 ` Rafael J. Wysocki
2012-10-02 6:33 ` [PATCH 02/10] ACPI: use device drivers_autoprobe to delay loading acpi drivers Yinghai Lu
2012-10-02 6:33 ` [PATCH 03/10] PCI: prepare to use device drivers_autoprobe to delay attach drivers Yinghai Lu
2012-10-02 6:33 ` [PATCH 04/10] PCI: Use device_add for device and bus early Yinghai Lu
2012-10-02 6:33 ` [PATCH 05/10] PCI, ACPI: Separate out acpi_pci_root_osc_contorl_set Yinghai Lu
2012-10-02 6:33 ` [PATCH 06/10] PCI, ACPI: Move hot add root bus conf code to acpi_pci_root_add Yinghai Lu
2012-10-02 6:33 ` [PATCH 07/10] PCI, ACPI: Remove not used acpi_pci_root_start() Yinghai Lu
2012-10-02 6:33 ` [PATCH 08/10] PCI: Add dev_is_pci_host_bridge() helper Yinghai Lu
2012-10-02 6:33 ` [PATCH 09/10] PCI, ACPI: using acpi/pci bind path for pci_host_bridge Yinghai Lu
2012-10-02 6:33 ` [PATCH 10/10] PCI, ACPI: use bus_type notifier for acpi_pci_bind_notify Yinghai Lu
2012-10-06 2:57 ` [PATCH 00/10] PCI, ACPI: Use bus type notifier for root bus hotplug Jiang Liu
2012-10-06 7:25 ` Yinghai Lu
2012-10-07 15:17 ` Jiang Liu
2012-10-07 22:33 ` Yinghai Lu
2012-10-08 15:23 ` Jiang Liu
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