From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423215AbXD3M7B (ORCPT ); Mon, 30 Apr 2007 08:59:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1423223AbXD3M7B (ORCPT ); Mon, 30 Apr 2007 08:59:01 -0400 Received: from mpc-26.sohonet.co.uk ([193.203.82.251]:47999 "EHLO moving-picture.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1423215AbXD3M67 (ORCPT ); Mon, 30 Apr 2007 08:58:59 -0400 Message-ID: <4635E810.80809@moving-picture.com> Date: Mon, 30 Apr 2007 13:58:56 +0100 From: James Pearson User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040524 X-Accept-Language: en-us, en MIME-Version: 1.0 To: "Antonino A. Daplas" CC: linux-kernel@vger.kernel.org Subject: Re: X display shift with disabled console blanking References: <46322E08.3040303@moving-picture.com> <1177727097.7568.6.camel@daplas> In-Reply-To: <1177727097.7568.6.camel@daplas> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Disclaimer: This email and any attachments are confidential, may be legally X-Disclaimer: privileged and intended solely for the use of addressee. If you X-Disclaimer: are not the intended recipient of this message, any disclosure, X-Disclaimer: copying, distribution or any action taken in reliance on it is X-Disclaimer: strictly prohibited and may be unlawful. If you have received X-Disclaimer: this message in error, please notify the sender and delete all X-Disclaimer: copies from your system. X-Disclaimer: X-Disclaimer: Email may be susceptible to data corruption, interception and X-Disclaimer: unauthorised amendment, and we do not accept liability for any X-Disclaimer: such corruption, interception or amendment or the consequences X-Disclaimer: thereof. Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Antonino A. Daplas wrote: > On Fri, 2007-04-27 at 18:08 +0100, James Pearson wrote: > >>I have a problem whereby the X display 'shifts' to left when anything >>writes to /dev/console - where console screen blanking has been disabled >>i.e. doing something like: >> >>boot to run level 3 >> >>If not root, then make sure /dev/console is writeable >> >>login and type: >> >>setterm -blank 0 >> >>start X >> >>type into an xterm: >> >>echo "some random text" > /dev/console >>(may have to repeat the echo above a few times) >> >>... and the whole X display jumps (and wraps) to the left >> >>I'm using a RHEL4 based distro with a vanilla 2.6.21 x86_64 kernel >>(although I've seen the problem with various x86_64 and i686 2.6.X kernels). >> >>I've seen this problem on a number of different nVidia cards - using >>the vesa driver (same problem occurs with nVidia's binary driver). I >>haven't tried using other makes of graphics cards. >> >> >>OK, this may be a strange combination of disabling the text console >>blanking and running X, but something isn't right somewhere ... > > > Yep, it's strange because I can't reproduce this. And the console write > should not succeed if the current console is in KD_GRAPHICS mode, which > is done by X (unless your version is different). I've just installed a vanilla CentOS 4.4 on an i686 SMP machine - with an nVidia Quadro4 980 XGL card. By default, this sets up X using the 'nv' driver (using RedHat's xorg-x11-6.8.2-1.EL.13.37). If I follow my 'recipe' above, then the screen shifts - note: it looks like you have to write several lines of text to /dev/console (at least 30) to trigger the problem (e.g. run the echo to /dev/console in a loop) - also, I've found that switching to the console and back to X (Ctrl-Alt-F1 then Ctrl-Alt-F7) while this echo loop is running can force the shift to start ... This is with the RedHat based 2.6.9-42.ELsmp kernel - but I also get the problem with a vanilla 2.6.21 kernel. >>Any ideas? > > > I don't. But, what is your current console? Is it VGA, or framebuffer? > Can you try doing this again in both VGA and vesafb? I'm not sure what the current console is - whatever is the default with RHEL4/CentOS4 - how do I select a different type of console? > And this does not happen if there is no previous setterm -blank 0 > command? It doesn't happen if there is no previous 'setterm -blank 0' - so, arguably, this is the 'fix' ... James Pearson