From mboxrd@z Thu Jan 1 00:00:00 1970 From: Raphael Assenat Subject: Re: [PATCH 1/2] mbxfb: Fix a chip bug? resulting in wrong pixclock Date: Tue, 15 Aug 2006 08:47:03 -0400 Message-ID: <44E1C247.8040004@8d.com> References: <44E0C3A4.6050407@8d.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 1GCyIt-0004r3-Dt for linux-fbdev-devel@lists.sourceforge.net; Tue, 15 Aug 2006 05:45:55 -0700 Received: from roc.holo.8d.com ([64.254.227.115]) by mail.sourceforge.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.44) id 1GCyIr-0005QM-0a for linux-fbdev-devel@lists.sourceforge.net; Tue, 15 Aug 2006 05:45:55 -0700 In-Reply-To: <44E0C3A4.6050407@8d.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: linux-fbdev-devel@lists.sourceforge.net Raphael Assenat wrote: > This is a workaround for what I think is a bug in the 2700G chip. > > The PLL output frequency is adustable using 3 values (M, N and P. See > code for formula). The N value range is documented to be 1 to 7 but when > it is set to 1, the output frequency is lower than it should be (divided > by 2), > giving unexpected results such as no sync on a CRT display. I just thought it might be useful to post information about how to reproduce this: Install fbset and link /etc/fb.modes to the fb.modes.ATI distributed with fbset. Do 'fbset "800x600-70" -depth 16' and the generated pixel clock will result in a v-sync around 25 hz. The 800x600-60 and 800x600-72 modes will work correctly, with the expected v-sync values. After applying the patch, the "800x600-70" mode works correctly. Here are the modelines from my fb.modes file, just in case: mode "800x600-70" # D: 44.90 MHz, H: 44.544 kHz, V: 70.04 Hz geometry 800 600 800 600 8 timings 22272 40 24 15 9 144 12 hsync high endmode mode "800x600-60" # D: 40.00 MHz, H: 37.879 kHz, V: 60.32 Hz geometry 800 600 800 600 8 timings 25000 88 40 23 1 128 4 hsync high vsync high endmode mode "800x600-72" # D: 50.00 MHz, H: 48.090 kHz, V: 72.19 Hz geometry 800 600 800 600 8 timings 20000 64 56 23 37 120 6 hsync high vsync high endmode ------------------------------------------------------------------------- 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