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News Autopolarity feature confuses Xircom Cards 

Forum: Xircom PCMCIA Ethernet Adapter Issues
Re: Question IRQ sharing and Xircom CardBus (RBEM56G-100BTX) (Anek Vorapanya)
Re: None Interrupt sharing is normal for PCI (David Hinds)
Re: Feedback Ethernet seems to be working but with some problem (Anek Vorapanya)
Date: 1999, Dec 17
From: Thomas Meckel tmeckel

Hi Guys,

i faced the same problems as Anek Vorapanya, lame performace
with my Xircom real port modem/lan card. I fixed the problem
by disabling the autopolarity feature in the csr14 register
for the 10baseT mode.
The following explanation is taken from the readme file out
of the recent windows driver release from Xircom:

--- snipp
Auto Polarity Correction
------------------------
Certain 10/100 switches (generally those using Broadcom
transceivers) implement automatic correction for polarity
reversed cables that is not completely compatible with the
same correction provided by the CBEM/RBEM.  If the network
speed is forced to 10Mbps, severe throughput problems may be
experienced.  To resolve this problem, a new Auto Polarity
keyword in the adapter's advanced properties has been added. 
If needed, the default setting of ON (meaning that the card
will compensate for reversed cables) can be set to OFF to
disable polarity correction.  This will restore normal
throughput. 
snapp ---

I plan to add a new option called "autopolarity" for the
tulip driver so that the user can specify if the card will
use this feature or not.

Cheers

Thomas

P.S.: Any comments welcome

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Messages Inline: 1 All Outline: 1 2 All

1. Question Untitled by Anek Vorapanya, 1999, Dec 18
(_ Feedback Patch for tulip_cb.c by Thomas Meckel, 1999, Dec 19

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