From owner-cvs-all  Mon May 14 14: 8:30 2001
Delivered-To: cvs-all@freebsd.org
Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21])
	by hub.freebsd.org (Postfix) with ESMTP
	id C4D2A37B43E; Mon, 14 May 2001 14:08:23 -0700 (PDT)
	(envelope-from imp@FreeBSD.org)
Received: (from imp@localhost)
	by freefall.freebsd.org (8.11.1/8.11.1) id f4EL8NS92464;
	Mon, 14 May 2001 14:08:23 -0700 (PDT)
	(envelope-from imp)
Message-Id: <200105142108.f4EL8NS92464@freefall.freebsd.org>
From: Warner Losh <imp@FreeBSD.org>
Date: Mon, 14 May 2001 14:08:21 -0700 (PDT)
To: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org
Subject: cvs commit: src/sys/pccard pcic.c
X-FreeBSD-CVS-Branch: HEAD
Sender: owner-cvs-all@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.ORG

imp         2001/05/14 14:08:21 PDT

  Modified files:
    sys/pccard           pcic.c 
  Log:
  Fix the so called "static bug" in polling mode.  Some desktop cards
  have bad grounding characteristics which allow small static discharges
  (or sunspots, we're not 100% sure which) to reach the bridge chip.
  This causes the bridge chip to wedge/reset itself.  There's no known
  cure short of rebooting.
  
  The bug manifests itself by the STAT_CHG return 0xff when read.  This
  is impossible because the upper bits are reserved (and therefore
  zero).  In addition, some of the lower bits are one only for memory
  cards, which OLDCARD doesn't support, so if they are set, something
  seriously foobar'd is going on.
  
  So far we've seen this in exactly one brand of pcmcia <-> isa bridge
  which plug and play identifies only as "VIA PCMCIA CARD".  This card
  just has buffers on the isa card and the actual bridge chip on the
  remote slot, which is connected by long ribbon cables.  We think this
  long cable run, coupled with the lack of coupling capacitors is a
  major reason why it is so static sensitive while its bretheren aren't.
  
  Work Supported by: Timing Solutions, Inc.
  
  MFC After: 3 days
  
  Revision  Changes    Path
  1.117     +34 -7     src/sys/pccard/pcic.c


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe cvs-all" in the body of the message