Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752872Ab3IVUDX (ORCPT ); Sun, 22 Sep 2013 16:03:23 -0400 Received: from mail-ie0-f177.google.com ([209.85.223.177]:51852 "EHLO mail-ie0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752338Ab3IVUDW (ORCPT ); Sun, 22 Sep 2013 16:03:22 -0400 MIME-Version: 1.0 X-Originating-IP: [178.83.130.250] In-Reply-To: <523F2390.5030702@math.tu-berlin.de> References: <4319_1379778790_523DC0E3_4319_13540_1_CAKMK7uHynzChMurTLAYMfeRF07aDJxes-6eSO1iDbrET8xD84Q@mail.gmail.com> <523F2390.5030702@math.tu-berlin.de> Date: Sun, 22 Sep 2013 22:03:21 +0200 Message-ID: Subject: Re: i835GM flicker on panning From: Daniel Vetter To: Thomas Richter Cc: Linux Kernel Mailing List , intel-gfx Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1896 Lines: 48 Hm, that sounds a bit more like the ddx is having fun with rendering. Have you tried switching the backed from to either SNA or UXA? Also adding relevant mailing lists ... -Daniel On Sun, Sep 22, 2013 at 7:06 PM, Thomas Richter wrote: > Hi folks, hi Daniel, > > there is still an issue with flicker on panning with the 835GM chipset. As > already explained, the flicker only appears if the panning position > satisfies certain alignment constraints, in specific. As long as the plane > pointer is aligned to 64 byte boundaries, everything works correctly. > > I tried now to add a parameter to the kernel to adjust the watermark level > of the chipset and see whether this makes any difference with regards to the > flicker. However, it does not. It seems that the trouble is not there. > > However, I noticed something interesting: If I use a non-native mode of the > display, i.e. enable the scaling feature of the DVO, everything works, and > no flicker ever appears. However, in these situations the resolution is also > lower than that of the native display, and hence the issue may also be > related to the PLL clock. > > I also noticed that if I invert the display, i.e. use the rotation feature, > even in the native resolution, nothing flickers, though panning is rather > slow. > > Does this somehow ring a bell? Can I somehow force the driver to use the > same logic for the regular display as for the inverted display to avoid the > flicker? > > Any help would be appreciated. > > Greetings, > Thomas > -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/