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Date: Tue, 17 Jul 2018 16:00:53 -0500
From: Bjorn Helgaas <helgaas@kernel.org>
To: Matthew Wilcox <willy@infradead.org>
Cc: Martin Mares <mj@ucw.cz>, Logan Gunthorpe <logang@deltatee.com>,
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Subject: Re: lspci: Display path to device
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 <20180717203900.GA1771@bombadil.infradead.org>
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On Tue, Jul 17, 2018 at 01:39:00PM -0700, Matthew Wilcox wrote:
> I don't like telling the user to grovel around lspci -t by hand.  It's
> not many lines of code to add a new -P option to lspci to show the path
> to each device instead of bus:dev.fn
> 
> Here's three examples, first without, then with -P.
> ...

> The Nehalem system makes an interesting testcase because it exposes some
> registers in fake PCIe devices that aren't behind the root ports.  eg:
> 
> ff:06.3 Host bridge: Intel Corporation Xeon 5500/Core i7 Integrated Memory Controller Channel 2 Thermal Control Registers (rev 04)

I think these appear as conventional PCI devices; at least the ones
I've seen, e.g., [1], don't have a PCIe capability, so I think it
makes sense that they're not behind a root port.

[1] https://bugzilla5.redhat.com/attachment.cgi?id=433169