From mboxrd@z Thu Jan 1 00:00:00 1970 From: Felix Kuehling Subject: Re: Flickering with page-flipping on Acer Iconia W500 (AMD C-50 APU) Date: Wed, 22 Feb 2012 11:20:22 -0500 Message-ID: <4F4515C6.2000206@amd.com> References: <4F29C00E.4020300@amd.com> <4F443BA9.301@tuebingen.mpg.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from TX2EHSOBE008.bigfish.com (tx2ehsobe005.messaging.microsoft.com [65.55.88.15]) by gabe.freedesktop.org (Postfix) with ESMTP id 4CD7F9E81B for ; Wed, 22 Feb 2012 08:35:30 -0800 (PST) In-Reply-To: <4F443BA9.301@tuebingen.mpg.de> 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: Mario Kleiner , Alex Deucher Cc: "Deucher, Alexander" , "Daenzer, Michel" , dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org On 12-02-21 07:49 PM, Mario Kleiner wrote: > On 02/21/2012 09:07 PM, Alex Deucher wrote: [snip] >> The fix looks ok to me. Mario any thoughts? >> >> Reviewed-by: Alex Deucher >> > > Hi, > > the fix looks ok to me for that device, but could we make it > conditional on the AMD C-50 APU and similar pieces? It is the right > thing to do for that gpu, but for regular desktop gpus it is too > pessimistic if it defers the pageflip timestamping and completion > event for an already completed flip: > > 1. Makes the timestamps 1 refresh too late, causing timing sensitive > software like mine to detect false positives -- reporting skipped > frames were there weren't any. Not as bad as missing a really skipped > frame, but still not great. Agreed. I was going to perform some more experiments on other hardware to determine what the right threshold is for different hardware generations. I hope I'll get to that this week. > > 2. Can reduce the framerate due to throttling the client, especially > on systems that are already challenged wrt. to their irq timing. > > Is the vblank period very short on these kind of devices? From Felix > description is sounds as if it is only 2 scanlines? It looks like that. Thanks for the feedback, Felix > > thanks, > -mario > -- _____ Felix Kuehling \ _ | MTS Software Development Eng. /|_| | SW-Linux Base Gfx | AMD |__/ \| T 905.882.2600 x8928