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From: Richard Yang <weiyang@linux.vnet.ibm.com>
To: linux-pci@vger.kernel.org
Subject: What is the difference between number and secondary in pci_bus?
Date: Sun, 1 Apr 2012 16:38:35 +0800	[thread overview]
Message-ID: <20120401083835.GA23662@richard> (raw)

All

In the structure of pci_bus.
There is number, primary, secondary and subordinate.

primary and subordinate are easy to understand, while the number and
secondary confused me. 

I think secondary means the current bus number.
Then what number stands for?

In pci_alloc_child_bus(), 
child->number = child->secondary = busnr;
So they are the same? 
Then we need two different field?

I search the git log while find these code is imported as the first
commit. So I don't see the history.

-- 
Richard Yang
Help you, Help me


             reply	other threads:[~2012-04-01  8:38 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-04-01  8:38 Richard Yang [this message]
2012-04-02 23:30 ` What is the difference between number and secondary in pci_bus? Bjorn Helgaas
2012-04-03 15:17   ` Richard Yang

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