Re: [PATCH] pci: fix no_pci_devices() #2

From: Jesse Barnes
Date: Mon Jan 05 2009 - 14:09:54 EST


On Saturday, December 20, 2008 3:14 am Vegard Nossum wrote:
> On Sat, Dec 20, 2008 at 11:56 AM, Vegard Nossum <vegard.nossum@xxxxxxxxx>
wrote:
> > On Sat, Dec 20, 2008 at 9:58 AM, Greg KH <gregkh@xxxxxxx> wrote:
> >> Care to make a patch for no_pci_devices() to work properly in this kind
> >> of situation?
> >
> > How does this look?
> >
> > I have introduced a variable pci_is_initiated, which is set after the bus
> > has been registered.
>
> This patch is simpler and also works for me. But I am not too fond of it
> either...
>
>
> Vegard
>
>
> From 1f047c86fc7a831d85174452da92344a3582a158 Mon Sep 17 00:00:00 2001
> From: Vegard Nossum <vegard.nossum@xxxxxxxxx>
> Date: Sat, 20 Dec 2008 12:08:18 +0100
> Subject: [PATCH] pci: fix no_pci_devices() #2
>
> In short, no_pci_devices() should not use bus_find_device() before
> initcalls have run, because the pci bus structure has not been
> initialized yet.
>
> Reference: http://lkml.org/lkml/2008/12/20/21
>
> Cc: Greg KH <gregkh@xxxxxxx>
> Cc: Pekka Enberg <penberg@xxxxxxxxxxxxxx>
> Signed-off-by: Vegard Nossum <vegard.nossum@xxxxxxxxx>
> ---
> drivers/base/bus.c | 1 +
> drivers/pci/probe.c | 3 +++
> 2 files changed, 4 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/base/bus.c b/drivers/base/bus.c
> index 5aee1c0..5e83faf 100644
> --- a/drivers/base/bus.c
> +++ b/drivers/base/bus.c
> @@ -931,6 +931,7 @@ bus_devices_fail:
> bus_uevent_fail:
> kset_unregister(&bus->p->subsys);
> kfree(bus->p);
> + bus->p = NULL;
> out:
> return retval;
> }
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 003a9b3..d561be7 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -35,6 +35,9 @@ int no_pci_devices(void)
> struct device *dev;
> int no_devices;
>
> + if (!pci_bus_type.p)
> + return 1;
> +
> dev = bus_find_device(&pci_bus_type, NULL, NULL, find_anything);
> no_devices = (dev == NULL);
> put_device(dev);

Assuming Greg already took the generic part, can you resend the PCI part to
the linux-pci@xxxxxxxxxxxxxxx list for review just in case anyone has a better
idea of how to do it?

Thanks,
--
Jesse Barnes, Intel Open Source Technology Center

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