From owner-freebsd-hardware Thu May 22 00:13:32 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.5/8.8.5) id AAA06443 for hardware-outgoing; Thu, 22 May 1997 00:13:32 -0700 (PDT) Received: from tfs.com (tfs.com [140.145.250.1]) by hub.freebsd.org (8.8.5/8.8.5) with SMTP id AAA06436 for ; Thu, 22 May 1997 00:13:29 -0700 (PDT) Received: from critter.dk.tfs.com by tfs.com (smail3.1.28.1) with SMTP id m0wUS2u-0003vyC; Thu, 22 May 97 00:12 PDT Received: from critter (localhost [127.0.0.1]) by critter.dk.tfs.com (8.8.5/8.8.5) with ESMTP id JAA00236; Thu, 22 May 1997 09:10:45 +0200 (CEST) To: Brett Glass cc: Michael Smith , gurney_j@resnet.uoregon.edu, rberndt@nething.com, WELCHDW@wofford.edu, HARDWARE@freebsd.org From: Poul-Henning Kamp Subject: Re: isa bus and boca multiport boards In-reply-to: Your message of "Wed, 21 May 1997 23:19:27 MDT." <3.0.1.32.19970521231927.006a1a5c@lariat.org> Date: Thu, 22 May 1997 09:10:45 +0200 Message-ID: <234.864285045@critter> Sender: owner-hardware@freebsd.org X-Loop: FreeBSD.org Precedence: bulk In message <3.0.1.32.19970521231927.006a1a5c@lariat.org>, Brett Glass writes: >At 01:51 PM 5/22/97 +0930, Michael Smith wrote: > >>The state of the 'gone' flag may (possibly) change >>_during_the_execution_ of the ISR. > >If so, it sounds as if there might be major synchronization and reentrancy >problems. Not to mention logic glitches if the port goes away at the wrong >moment. There is. PCMCIA >REALLY< botched this one. At least they could have made sure that you got a defined value back if you read from a port that has recently gone AWOL, but no, gone with the wind and fair wind! :-( -- Poul-Henning Kamp | phk@FreeBSD.ORG FreeBSD Core-team. http://www.freebsd.org/~phk | phk@login.dknet.dk Private mailbox. whois: [PHK] | phk@tfs.com TRW Financial Systems, Inc. Power and ignorance is a disgusting cocktail.