From: Bjorn Helgaas <bjorn.helgaas@hp.com>
To: Alex Chiang <achiang@hp.com>
Subject: Re: [PATCH v2 07/11] ACPI: acpi_pci_unbind should clean up properly after acpi_pci_bind
Date: Fri, 5 Jun 2009 09:49:01 -0600
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Cc: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>, lenb@kernel.org,
       linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org,
       linux-pci@vger.kernel.org
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On Thursday 04 June 2009 05:35:21 pm Alex Chiang wrote:
> * Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>:
> >
> > I have a concern about this change.
> >
> > The acpi_pci_irq_del_prt() against dev->bus removes not only
> > the _PRT entries for PCI function corresponding to specified
> > acpi_device, but also other _PRT entries for working PCI
> > devices/functions on the same bus. As a result, interrupt
> > initialization for those PCI functions would no longer work
> > properly after that.
> >
> > So I think we should not call acpi_pci_irq_del_prt() against
> > dev->bus.
> 
> Thanks for the review. I agree with you.

I agree that this respun version makes things more the way they were,
so in that sense, it should do no harm.  But I still have the niggling
concern that .bind() adds _PRT info for non-bridges, and there's no
corresponding removal.  There should be some path that makes this
more symmetric.

> Here is a respun version of this patch.
> 
> From: Alex Chiang <achiang@hp.com>
> 
> ACPI: acpi_pci_unbind should clean up properly after acpi_pci_bind
> 
> In acpi_pci_bind, we set device->ops.bind and device->ops.unbind, but
> never clear them out.
> 
> Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
> Signed-off-by: Alex Chiang <achiang@hp.com>
> ---
> diff --git a/drivers/acpi/pci_bind.c b/drivers/acpi/pci_bind.c
> index 62cb383..c9cc650 100644
> --- a/drivers/acpi/pci_bind.c
> +++ b/drivers/acpi/pci_bind.c
> @@ -109,11 +109,13 @@ static int acpi_pci_unbind(struct acpi_device *device)
>  	struct pci_dev *dev;
>  
>  	dev = acpi_get_pci_dev(device->handle);
> -	if (!dev)
> +	if (!dev || !dev->subordinate)
>  		return 0;
>  
> -	if (dev->subordinate)
> -		acpi_pci_irq_del_prt(dev->subordinate);
> +	acpi_pci_irq_del_prt(dev->subordinate);
> +
> +	device->ops.bind = NULL;
> +	device->ops.unbind = NULL;
>  
>  	pci_dev_put(dev);
>  	return 0;
> 


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