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Date: Tue, 5 Jun 2012 14:35:38 +0800
From: Ram Pai <linuxram@us.ibm.com>
To: Yinghai Lu <yinghai@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>, Ram Pai <linuxram@us.ibm.com>,
	Richard Yang <weiyang@linux.vnet.ibm.com>,
	linux-pci@vger.kernel.org, Gavin Shan <shangw@linux.vnet.ibm.com>
Subject: Re: One chart on pci bridge and its bus and their children
Message-ID: <20120605063538.GE6637@ram-ThinkPad-T61>
Reply-To: Ram Pai <linuxram@us.ibm.com>
References: <20120605032627.GA23271@richard>
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On Mon, Jun 04, 2012 at 10:20:51PM -0700, Yinghai Lu wrote:
> On Mon, Jun 4, 2012 at 10:18 PM, Yinghai Lu <yinghai@kernel.org> wrote:
> > On Mon, Jun 4, 2012 at 9:37 PM, Bjorn Helgaas <bhelgaas@google.com> wrote:
> >> That's true, but I don't think it answers the question.  If we have:
> >>
> >>    pci_bus->bridge == pci_bus->self->dev
> >>
> >> why would we need both "self" and "bridge"?  It would be interesting
> >> to try to remove "bridge" and replace uses of it with "self->dev".
> >
> > then how about root bus?
> >
> > root bus ->self should be NULL.
> >
> > root bus ->bridge is to the hostbridge->dev.

Yinghai,

is there a reason why this can't be fixed in
pci_create_root_bus() by having
   bus->self = bridge; /* 'bridge' is the pci_device of the corresponding host bridge */
   get_device(&bridge->dev);


RP