From owner-freebsd-arch@FreeBSD.ORG Sat Jan 21 01:45:18 2012 Return-Path: Delivered-To: freebsd-arch@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B888D106566C for ; Sat, 21 Jan 2012 01:45:18 +0000 (UTC) (envelope-from imp@bsdimp.com) Received: from harmony.bsdimp.com (bsdimp.com [199.45.160.85]) by mx1.freebsd.org (Postfix) with ESMTP id 6AAA98FC12 for ; Sat, 21 Jan 2012 01:45:18 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by harmony.bsdimp.com (8.14.4/8.14.3) with ESMTP id q0L1hRjb047153; Fri, 20 Jan 2012 18:43:36 -0700 (MST) (envelope-from imp@bsdimp.com) Mime-Version: 1.0 (Apple Message framework v1084) Content-Type: text/plain; charset=us-ascii From: Warner Losh In-Reply-To: <66DDA0A2-F878-43FF-8824-54868F493B18@lassitu.de> Date: Fri, 20 Jan 2012 19:43:33 -0600 Content-Transfer-Encoding: quoted-printable Message-Id: <8EF24110-C985-400F-ADDF-B1D63C4E304B@bsdimp.com> References: <8D025847-4BE4-4B2C-87D7-97E72CC9D325@lassitu.de> <20120104215930.GM90831@alchemy.franken.de> <47ABA638-7E08-4350-A03C-3D4A23BF2D7E@lassitu.de> <1763C3FF-1EA0-4DC0-891D-63816EBF4A04@lassitu.de> <20120106182756.GA88161@alchemy.franken.de> <95372FB3-406F-46C2-8684-4FDB672D9FCF@lassitu.de> <20120106214741.GB88161@alchemy.franken.de> <20120108130039.GG88161@alchemy.franken.de> <23477898-8D85-498C-8E30-192810BD68A8@lassitu.de> <20120111193738.GB44286@alchemy.franken.de> <66DDA0A2-F878-43FF-8824-54868F493B18@lassitu.de> To: Stefan Bethke X-Mailer: Apple Mail (2.1084) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0.1 (harmony.bsdimp.com [127.0.0.1]); Fri, 20 Jan 2012 18:43:37 -0700 (MST) Cc: FreeBSD-arch Subject: Re: Extending sys/dev/mii X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 21 Jan 2012 01:45:18 -0000 On Jan 20, 2012, at 5:08 PM, Stefan Bethke wrote: > The second problem is that there's currently no way to express a = dependency between two devices other than a parent-child relationship. = I would be interested to learn why this appears to be so uncommon that I = could not find any discussion of such a feature. Has it really never = before come up? Sure there is: you can do it by name. I wrote a driver that attached to = the ISA bus, but also needed to talk to the ppbus that was attached to = the printer. My solution was to have a post-attach name-lookup so that = it could then call methods on the other driver's device_t. I wonder why = we can't do that here? Warner