Subject: Re: gem (ERI/GEM/GMAC Ethernet device driver) has problems on macppc
To: Steven M. Bellovin <>
From: Timo Schoeler <>
List: current-users
Date: 10/21/2005 10:28:20
Steven M. Bellovin wrote:
> In message <>, Timo Schoeler writes:
>>Steven M. Bellovin wrote:
>>>In message <>, Timo Schoeler writes:
>>>>i said on a plain dumb SMC 10/100 _hub_ this problem appears. then i 
>>>>tried the Nortel 450 (_switch) -- this runs fine in full duplex mode. 
>>>>when i then manually set both the switch (managed) and the G4 to half 
>>>>duplex, the problem occurs again.
>>>>when using the SMC _hub_ the machine automatically sets the NIC to half 
>>>>duplex as it should be.
>>>In other words, whenver your machine is supposed to use half-duplex, 
>>>you get these failures, whether the setting is manual or automatic.  I 
>>>don't know if it's a bug in the chip or the driver, though.  I don't 
>>>recall all of the details of this thread, but how do other OSs behave?  
>>>Do any succeed in such a situation? If so, it's probably a driver bug.
>>>		--Steven M. Bellovin,
>>neither Mac OS 'Classic' nor Mac OS X show those errors (for the former 
>>one i have to check on the switch for CRC errors etc.). NetBSD is the 
>>only OS having trouble with this.
> I think we've diagnosed the problem to some extent.  I can't help any 
> more, since I know nothing of this board or PPCs.  I suggest you 
> send-pr, including this analysis -- that it's a collision problem in 
> half-duplex mode, manual or automatic -- and hope that someone who does 
> know that NIC can help.
> 		--Steven M. Bellovin,

i filed a PR [0] -- No. 31858 -- Tue Oct 18 20:16:27 2005 and asked on 
the list whether anyone has seen this, too. a thing to avoid, it seems?


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