From mboxrd@z Thu Jan 1 00:00:00 1970 From: bugzilla-daemon@freedesktop.org Subject: [Bug 48880] Set mode has different timings than requested on VGA Date: Thu, 19 Apr 2012 13:45:19 +0000 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from annarchy.freedesktop.org (annarchy.freedesktop.org [131.252.210.176]) by gabe.freedesktop.org (Postfix) with ESMTP id BAD8A9EBBC for ; Thu, 19 Apr 2012 06:45:19 -0700 (PDT) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org Errors-To: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org To: dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org https://bugs.freedesktop.org/show_bug.cgi?id=48880 --- Comment #15 from Luc Verhaegen 2012-04-19 06:45:19 PDT --- Alex, i thi(In reply to comment #14) > > As I said before some monitors are really picky about the clocks they get. The > pixel clock is generated from a reference clock and a set of dividers. In some > cases it's not possible to get exactly the pixel clock of the mode, so the > driver gets as close as possible. The two clocks produced are 148.43 Mhz and > 148.57 Mhz. Both are within 0.07 Mhz of the actual clock. Some monitors don't > like clocks that are slightly lower, others don't like clocks that are slightly > higher, others don't care. In some cases you even have monitors that don't > like certain divider combinations that produce the exact same pixel clock. As > you can see from comment 11, even your own monitor is happy and not happy with > the same pixel clock depending on the connection. > > I'd be leery of changing the pll flags without a lot of thorough testing since > these change may break certain modes on other monitors. Did you try > RADEON_PLL_USE_FRAC_FB_DIV? It should help the driver get closer to the actual > pixel clock by allowing a finer grained fb divider, but once again, some > monitors are picky about certain divider combinations. I'd be more inclined to > add this flag than the MINM_OVER_MAXP flag however. Err, Alex, i think that it is the display engine, for a particular version and process, that has issues with certain divider combinations which should theoretically produce the same pixel clock, not the monitor. -- Configure bugmail: https://bugs.freedesktop.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the assignee for the bug.