From owner-freebsd-hackers@FreeBSD.ORG Tue May 20 13:37:59 2008 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 38E89106564A; Tue, 20 May 2008 13:37:59 +0000 (UTC) (envelope-from avg@icyb.net.ua) Received: from falcon.cybervisiontech.com (falcon.cybervisiontech.com [217.20.163.9]) by mx1.freebsd.org (Postfix) with ESMTP id DB94E8FC22; Tue, 20 May 2008 13:37:58 +0000 (UTC) (envelope-from avg@icyb.net.ua) Received: from localhost (localhost [127.0.0.1]) by falcon.cybervisiontech.com (Postfix) with ESMTP id CF9C7744005; Tue, 20 May 2008 16:37:56 +0300 (EEST) X-Virus-Scanned: Debian amavisd-new at falcon.cybervisiontech.com Received: from falcon.cybervisiontech.com ([127.0.0.1]) by localhost (falcon.cybervisiontech.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id bDVWcwrMWOJs; Tue, 20 May 2008 16:37:56 +0300 (EEST) Received: from [10.2.1.87] (gateway.cybervisiontech.com.ua [88.81.251.18]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by falcon.cybervisiontech.com (Postfix) with ESMTP id 328FC744004; Tue, 20 May 2008 16:37:56 +0300 (EEST) Message-ID: <4832D432.2050907@icyb.net.ua> Date: Tue, 20 May 2008 16:37:54 +0300 From: Andriy Gapon User-Agent: Thunderbird 2.0.0.12 (X11/20080311) MIME-Version: 1.0 To: John Baldwin References: <1210616585.00069210.1210605002@10.7.7.3> <1210627393.00069294.1210614002@10.7.7.3> <1211221409.00072277.1211209802@10.7.7.3> <1211246591.00072455.1211234402@10.7.7.3> In-Reply-To: <1211246591.00072455.1211234402@10.7.7.3> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-hackers@freebsd.org, RW Subject: Re: i386 cpu_reset_real: code/comment mismatch 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: Tue, 20 May 2008 13:37:59 -0000 on 20/05/2008 00:51 John Baldwin said the following: > So, the comment is correct and not the code. Curiously enough, OpenSolaris > does the same thing (it writes 0x2 followed by 0x6), but it has some sort of > comment which implies that you have to do a write to set or clear bit 1 > before setting bit 2. Linux only uses 0xcf9 on a specific x86 machine (View > workstation or some such) in which case it just does a single write of 0x6. > I'll test locally to make sure 0x4 and 0x6 both work and if so I will commit > the fix. And this code is most likely never reached in majority of the cases, reset via keyboard controller should just work. BTW, I understand that there is a difference between hard and soft reset in terms of hardware signals being asserted, but I don't quite understand general consequences. I.e. what is a practical difference between hard and soft reset? -- Andriy Gapon