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Date: Tue, 5 Jun 2012 13:41:32 +0800
From: Richard Yang <weiyang@linux.vnet.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: <20120605054132.GB24358@richard>
Reply-To: Richard Yang <weiyang@linux.vnet.ibm.com>
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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.
>
>also
>
>b->bridge = get_device(&bridge->dev);
>
>so there is one reference held by pci bus.

Hmm... so can we just have b->bridge, and then convert bridge to self if
necessary?

-- 
Richard Yang
Help you, Help me