Subject: Re: gem (ERI/GEM/GMAC Ethernet device driver) has problems on macppc -current
To: Timo Schoeler <firstname.lastname@example.org>
From: Steven M. Bellovin <email@example.com>
Date: 10/21/2005 04:23:48
In message <4358A3E0.firstname.lastname@example.org>, Timo Schoeler writes:
>Steven M. Bellovin wrote:
>> In message <43589E84.email@example.com>, 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, http://www.cs.columbia.edu/~smb
>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, http://www.cs.columbia.edu/~smb