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Subject: Re: [PATCH 3/5] Float the pci bus number on MPC8641HPCN board.
From: Wade Farnsworth <wfarnsworth@mvista.com>
To: Zhang Wei <wei.zhang@freescale.com>
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Date: Tue, 22 May 2007 10:59:52 -0700
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Cc: linuxppc-dev@ozlabs.org, paulus@samba.org
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On Tue, 2007-05-22 at 11:38 +0800, Zhang Wei wrote:
>  int mpc86xx_exclude_device(u_char bus, u_char devfn)
>  {
> +	struct pci_controller *hose;
> +
> +	hose = pci_bus_to_hose(bus);
> +	if (unlikely(!hose))
> +		return PCIBIOS_DEVICE_NOT_FOUND;
> +
> +	/* Correcting the hose->bus_offset value. */
> +	out_be32(hose->cfg_addr, 0x80000000 | ((hose->first_busno
> +					- hose->bus_offset) << 16));
> +	if (unlikely(in_le32(hose->cfg_data) == 0xffffffff))
> +		hose->bus_offset = hose->bus_offset ? 0 : hose->first_busno;
> +
>  	return PCIBIOS_SUCCESSFUL;
>  }

What is the purpose of this code and why put it in
mpc86xx_exclude_device?

--Wade