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Date: Fri, 26 Oct 2012 09:12:12 +0200
From: Gerd Hoffmann <kraxel@redhat.com>
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Subject: Re: xhci Portsc register issue
References: <CALuomMuUD4xSaCUT6MZn3ZV2gjXnuBUhkz78PgXZ6XgV4e-NvA@mail.gmail.com> <20121025153552.GA5205@xanatos>
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  Hi,

> But I'm not sure, since I've never attempted to memory map PCI registers
> from userspace.  I was under the impression that you just can't do that.

You can mmap /sys/bus/pci/devices(${device}/resource0.  Just hacked up a
tool which dumps the capability registers this way:

http://www.kraxel.org/cgit/usb-tools/tree/usb-print-caps.c

cheers,
  Gerd