From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752279AbbAXG5i (ORCPT ); Sat, 24 Jan 2015 01:57:38 -0500 Received: from mail-pd0-f178.google.com ([209.85.192.178]:49277 "EHLO mail-pd0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750900AbbAXG5g (ORCPT ); Sat, 24 Jan 2015 01:57:36 -0500 Date: Fri, 23 Jan 2015 22:57:32 -0800 From: Jeremiah Mahler To: Matt Roper , Chris Wilson , Daniel Vetter , Ville =?utf-8?B?U3lyasOkbMOk?= , Jani Nikula , David Airlie , Alex Deucher , Dave Airlie , Ander Conselvan de Oliveira , linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: Re: [Intel-gfx] [BUG, bisect] drm/i915: mouse pointer lags and overshoots Message-ID: <20150124065732.GA17057@hudson.localdomain> Mail-Followup-To: Jeremiah Mahler , Matt Roper , Chris Wilson , Daniel Vetter , Ville =?utf-8?B?U3lyasOkbMOk?= , Jani Nikula , David Airlie , Alex Deucher , Dave Airlie , Ander Conselvan de Oliveira , linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org References: <20150117100635.GA1281@hudson.localdomain> <20150119090847.GQ10649@intel.com> <54BCE1BF.5050808@intel.com> <20150119110404.GA26577@nuc-i3427.alporthouse.com> <20150119164024.GI22549@intel.com> <20150120054842.GN26519@phenom.ffwll.local> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150120054842.GN26519@phenom.ffwll.local> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org all, On Tue, Jan 20, 2015 at 06:48:42AM +0100, Daniel Vetter wrote: > On Mon, Jan 19, 2015 at 08:40:24AM -0800, Matt Roper wrote: > > On Mon, Jan 19, 2015 at 11:04:04AM +0000, Chris Wilson wrote: > > > On Mon, Jan 19, 2015 at 11:51:43AM +0100, Daniel Vetter wrote: > > > > There's also an issue in (most) X drivers which exaberates this > > > > issues: When changing the cursor buffer the X cursor code does a a) > > > > disable cursor b) update cursor image c) enable cursor cycle. > > > > > > Notably not -intel on which the bug has been observed. And more > > > importantly, the slow downs don't seem to correlate with cursor change, > > > just cursor movement. > > > -Chris > > > > > > -- > > > Chris Wilson, Intel Open Source Technology Centre > > > > It seems that the simple fix for this case (movement only) is to just > > skip the prepare_fb/cleanup_fb calls (and the associated vblank wait) in > > the transitional plane helper when newfb == oldfb. I just posted a > > small patch that makes that change (and solves the cursor lag for me). > > > > This won't solve the case if userspace uses a different framebuffer for > > each update (while trying to update faster than the refresh rate). Is > > there any existing userspace that behaves this way that we can test > > with? > > Hm, I've thought I've merged that patch already: > > commit ab58e3384b9f9863bfd029b458ff337d381bf6d2 > Author: Daniel Vetter > Date: Mon Nov 24 20:42:42 2014 +0100 > > drm/atomic-helper: Skip vblank waits for unchanged fbs > > Or is the problem here that the transitional plane helpers aren't up to > the task? If so please reference that in your patch. > > And we still need a hack for the "changed fb cursor" issue, I'll whip > something up. > -Daniel > -- > Daniel Vetter > Software Engineer, Intel Corporation > +41 (0) 79 365 57 48 - http://blog.ffwll.ch Just checking if anyone has come up with a fix. I am still stuck at next-20150112 because of this bug. -- - Jeremiah Mahler