From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ondrej Zary Date: Fri, 06 Aug 2010 15:35:08 +0000 Subject: matroxfb - wrong PLL calculation for Mystique and Mystique 220 Message-Id: <201008061735.09854.linux@rainbow-software.org> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-fbdev@vger.kernel.org Hello, there is a long-standing problem in matroxfb (and also with xf86-video-mga) with PLL values calculation. It results in "wavy" vertical lines at least on Mystique and Mystique 220, especially where dotted horizontal lines are displayed. On non-220 Mystique in 1024x768@85Hz, matroxfb calculates: m=0x0f, n=0x69, p=0x00 (producing wavy vertical lines) Windows driver calculates: m=0x03, n=0x34, p=0x01 (producing straight vertical lines) The resulting f_vco from windows values is 189713.5, which is above max_freq for this card. So it looks like the assumption that f_vco must be less or equal to max_freq is wrong. Could someone with access to MGA1064/1164 documentation look into this? xf86-video-mga bug (with photos of the screen): http://bugs.xfree86.org/show_bug.cgi?id14 -- Ondrej Zary