From mboxrd@z Thu Jan 1 00:00:00 1970 From: Petr Vandrovec Subject: Re: matroxfb-fix-dvi-setup-to-be-more-compatible.patch introduces jitter Date: Thu, 10 Aug 2006 21:45:48 +0200 Message-ID: <44DB8CEC.2080109@vc.cvut.cz> References: <689964845@web.de> <44DB64EB.3020007@us.ibm.com> Reply-To: linux-fbdev-devel@lists.sourceforge.net Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list1-new.sourceforge.net with esmtp (Exim 4.43) id 1GBGTb-00055K-0D for linux-fbdev-devel@lists.sourceforge.net; Thu, 10 Aug 2006 12:45:55 -0700 Received: from mailgw.cvut.cz ([147.32.3.235]) by mail.sourceforge.net with esmtp (Exim 4.44) id 1GBGTZ-0001pS-JP for linux-fbdev-devel@lists.sourceforge.net; Thu, 10 Aug 2006 12:45:54 -0700 In-Reply-To: <44DB64EB.3020007@us.ibm.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-fbdev-devel-bounces@lists.sourceforge.net Errors-To: linux-fbdev-devel-bounces@lists.sourceforge.net To: "Paul A. Clarke" Cc: linux-fbdev-devel@lists.sourceforge.net Paul A. Clarke wrote: > I've been looking deeper into this problem, which was reportedly > introduced by my patch a while ago, in Linux kernel 2.6.17. I don't > doubt the reports, but I'd like to replicate the problem as seen on the > x86 boxes as reported in kernel bug 6720 and a few others directly to > me, so I can verify a fix (if/when I can create one). > > So, I installed SLES 10 on an old x86 box, with a PCI G450 (actually an > IBM GXT135P). I verified that my patch is _not_ included in that kernel > (2.6.16.21). However, I see jittery DVI-D output at all times. I've > tried 640x480@60Hz, 1280x1024@60Hz, different "vesa" mode parameters > (0x11b, 0x1bb), XServer "-fbbpp 32". I usually end up losing sync with > the monitor after a few minutes. > > I don't have much experience with the G450 on x86, but I'm quite > surprised. Has anyone else observed this? I believe that problem is not x86 vs. ppc, but type of monitor you have connected to the box. Perhaps try walkdvi (http://platan.vc.cvut.cz/ftp/pub/linux/matrox-latest/walkdvi.tar.gz, it will probably need some fixes for big endian) with different XDVICLKCTL values. Code to set XPANMODE (in g450_set_plls) was written based on experimenting with couple of devices I had, so maybe right thing is not modifying XDVICLKCTL register, but instead teaching PLL code to try different XPANMODE values if PLL does not lock in reasonable time. Petr ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642