title: Why can I not change the PCI configuration registers on linux?
body: <p>I want to change Vendor_ID and Device_ID from a PCI device.
  However, every change I make will not save and I have no clue why.</p>
  
  <p>First I tried making changes using <em>setpci</em> which results in this:</p>
  
  <pre><code># sudo setpci -s 01:00.0 00.w
  # 8086
  # sudo setpci -s 01:00.0 00.w=168C
  # sudo setpci -s 01:00.0 00.w
  # 8086
  </code></pre>
  
  <p>Then I tried making the same changes using two different hex editors, editing the <em>config</em> file located in <em>/sys/bus/pci/devices/0000:01:00.0/</em>, but after saving, the file seems unchanged.
  I did open it as root and I don't get any errors when saving.</p>
  
  <p>I also tried <em>ethtool</em>, but it cannot even access the registers:</p>
  
  <pre><code># sudo ethtool -e wlan0
  # Cannot get EEPROM data: Operation not supported
  </code></pre>
  
  <p>I tried everything of the above on both Lubuntu 15.10 and Knoppix 7.6, resulting in the exact same behaviour.</p>
  
  <p>So, why does this happen?
  If the registers are protected, is there a way to unprotect them?</p>
  
  <p>Some more information:</p>
  
  <ul>
  <li>The mentioned pci device is a Intel 7260-AC Wireless Network Adapter</li>
  <li>I want the BIOS to recognize it as a Qualcomm Atheros AR9485 Wireless Network Adapter, because it's whitelist blocks everything else.</li>
  <li>Modifying the BIOS is not an option.</li>
  <li>I'm running Lubuntu and Knoppix from a USB drive</li>
  </ul>