Difference between revisions of "Problem with error 01C9 - More than one Ethernet devices"

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(Affected Models)
(Affected Models)
Line 16: Line 16:
  
 
Not affected are:
 
Not affected are:
*ThinkPad [[:Category:T23|T23]](most), [[:Category:T40|T40]]
+
*ThinkPad [[:Category:T23|T23]] (most), [[:Category:T40|T40]]
 
*ThinkPad [[:Category:X40|X40]]
 
*ThinkPad [[:Category:X40|X40]]
  

Revision as of 00:21, 1 February 2006

Problem Description

Certain ThinkPads show a warning message during POST when a WLAN card with an Atheros chipset is present in the MiniPCI slot:

  WARNING
  01C9: More than one Ethernet devices are found. Remove one of them.
  Press <Esc> to continue.

At POST, the BIOS conducts a scan for ethernet devices. It does this by reading the "PCI Class Codes" of every connected device. If more than one ethernet device is found, it produces the 01C9 error message. Unlike other wireless cards, which identify themselves as "other" network adapters, Atheros identify themselves as "ethernet". This collides with the internal ethernet controller (also a PCI device) and produces the 01C9.

Affected Models

Not affected are:

Solution

The solution is to modify the Atheros EEPROM so that the card correctly identifies itself as a "other" instead of "ethernet" network adapter. No messing with vendor and device ID is necessary. Madwifi drivers will function properly.

(code to do this in Linux will be posted)