From owner-freebsd-hackers@FreeBSD.ORG Sat Apr 24 15:36:19 2010 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 531951065698; Sat, 24 Apr 2010 15:36:16 +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 0AB4B8FC12; Sat, 24 Apr 2010 15:36:15 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by harmony.bsdimp.com (8.14.3/8.14.1) with ESMTP id o3OFTJuj034523; Sat, 24 Apr 2010 09:29:19 -0600 (MDT) (envelope-from imp@bsdimp.com) Date: Sat, 24 Apr 2010 09:29:38 -0600 (MDT) Message-Id: <20100424.092938.1125510371197586607.imp@bsdimp.com> To: gljennjohn@googlemail.com From: "M. Warner Losh" In-Reply-To: <20100424102255.12d782f8@ernst.jennejohn.org> References: <4BD22CD0.7030407@mittelstaedt.us> <20100424102255.12d782f8@ernst.jennejohn.org> X-Mailer: Mew version 6.3 on Emacs 22.3 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: tedm@mittelstaedt.us, freebsd-hackers@freebsd.org, freebsd-drivers@freebsd.org Subject: Re: What tty changes - question on porting ltmdm and hcfmdm to FreeBSD 8 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 24 Apr 2010 15:36:19 -0000 In message: <20100424102255.12d782f8@ernst.jennejohn.org> Gary Jennejohn writes: : On Fri, 23 Apr 2010 16:27:12 -0700 : Ted Mittelstaedt wrote: : : > Setting aside the question of why do we break software that a lot of : > people use : > (these chips are in use on a lot of laptops) is there a document : > somewhere that explains : > what changes need to be made in code for this new tty setup? Or, is : > there a set : > of magic include files or a "conversion shim" library that will allow : > these kinds : > of programs to build without much work? : > : > Or is porting these drivers just so non-trivial that the only way is : > to just delve into : > the system manuals and delve into the driver code and try to figure out : > what is : > going on in each? If that's the case that's probably beyond my ability : > but I'd : > be happy to serve as a testbed. : > : : The guy to ask about this would be Ed Schouten (ed@). AFAICR he did the new : TTY stuff. I don't know whether he reads these lists. : : AFAIK there is no easy way to fix this and there are no backwards compati- : bilty shims or magic header files. : : The fundamental problem with ltmdm is that it's a KLD and has to grovel : around in the guts of the kernel. That makes fixing it decidely non- : trivial. The fundamental reason that things changed was due to the locking of the TTY layer. These things change over time, and the old APIs made it very difficult to lock without driver visible changes. Warner