From owner-freebsd-bugs@freebsd.org Mon Dec 4 21:28:44 2017 Return-Path: Delivered-To: freebsd-bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 053F5E6B402 for ; Mon, 4 Dec 2017 21:28:44 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id E63ED7A42C for ; Mon, 4 Dec 2017 21:28:43 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id vB4LShaU008996 for ; Mon, 4 Dec 2017 21:28:43 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 224069] (Fix included) Use of uninitalized register value in vesa.ko, causing X, text console and suspend/resume to fail Date: Mon, 04 Dec 2017 21:28:43 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 11.1-STABLE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Many People X-Bugzilla-Who: sblachmann@gmail.com X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 04 Dec 2017 21:28:44 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D224069 --- Comment #8 from Stefan B. --- (In reply to Jung-uk Kim from comment #4, #5 and #6) #4: Didn't know about register zeroing. Such was not common back then when I did VGA programming via hardware and INT10 decades ago using mixed C and assembly back in the 16-bit DOS times. The sysctl tip is great for debugging! #5 No, you don't deserve that at all. When I saw the commit Mark pointed me at, I instantly recognized that it wa= s a lot of work involved. And you know, the bigger the work, the easier it is to overlook a detail. See please my comment #3, too. And I did not know you were the one who implemented FreeBSD suspend/resume. That was great work, good to know. Thank you! However, I think the suspend/resume thing has been neglected, and it does n= ot=20 work for many people. Below I discuss part of possible reasons. Btw, are you still interested in improving suspend/resume from STR to STD? #6 That is very interesting, because: In the FreeBSD forums, there are constant complaints regarding Nvidia cards= .=20 Garbled display when switching between console and X, and after resume. I h= ave made the discovery that this apparently *only* happens when vesa.ko is pres= ent. And that is in the GENERIC kernel or as loaded module. In the forums I have talked much of that problem. Apparently all people that followed my advice to build a custom kernel *without* option VESA and switch from vt to sc console (because the default vt console pulls in vesa.ko, if = not present in kernel), got rid of these problems. And, in my naive opinion I think suspend/resume should *not* be broken by j= ust doing kldload vesa.ko. (this is factually the way to reproduce the problem) So I have the strong feeling that there is a serious problem with the vesa module. But that is just my (possibly misleading) intuition. --=20 You are receiving this mail because: You are the assignee for the bug.=