From owner-freebsd-current Fri Dec 20 13:16:35 2002 Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 09A7937B401 for ; Fri, 20 Dec 2002 13:16:35 -0800 (PST) Received: from mailman.zeta.org.au (mailman.zeta.org.au [203.26.10.16]) by mx1.FreeBSD.org (Postfix) with ESMTP id C846043EE8 for ; Fri, 20 Dec 2002 13:16:33 -0800 (PST) (envelope-from bde@zeta.org.au) Received: from katana.zip.com.au (katana.zip.com.au [61.8.7.246]) by mailman.zeta.org.au (8.9.3/8.8.7) with ESMTP id IAA01574; Sat, 21 Dec 2002 08:16:11 +1100 Date: Sat, 21 Dec 2002 08:17:53 +1100 (EST) From: Bruce Evans X-X-Sender: bde@gamplex.bde.org To: Scott Long Cc: Sean Kelly , Nate Lawson , Subject: Re: `cat /dev/io` leads to system lockup. In-Reply-To: <3E02F56C.7080002@btc.adaptec.com> Message-ID: <20021221081335.P2641-100000@gamplex.bde.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Fri, 20 Dec 2002, Scott Long wrote: > Many peripheral hardware device do not like having their registers > blindly read (it's quite common for a read operation on a register to > signal an ASIC that it's ok to do a certain action) and will respond > with nasty things like interrupt storms, endless PCI target aborts, etc. > Whether this is silly or not is not the point; this is just one of the > many places in Unix that have no seatbelts and assume that the superuser > knows what he is doing. This is irrelevant, since "cat /dev/io" doesn't access device registers. Bruce To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message