Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936325AbcJUUCp (ORCPT ); Fri, 21 Oct 2016 16:02:45 -0400 Received: from mail.fireflyinternet.com ([109.228.58.192]:50305 "EHLO fireflyinternet.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S936186AbcJUUCn (ORCPT ); Fri, 21 Oct 2016 16:02:43 -0400 X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Date: Fri, 21 Oct 2016 21:02:27 +0100 From: Chris Wilson To: Takashi Iwai , Ville =?iso-8859-1?Q?Syrj=E4l=E4?= , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Noralf =?iso-8859-1?Q?Tr=F8nnes?= , David Airlie Subject: Re: [PATCH] drm/fb-helper: Don't call dirty callback for untouched clips Message-ID: <20161021200227.GU25629@nuc-i3427.alporthouse.com> Mail-Followup-To: Chris Wilson , Takashi Iwai , Ville =?iso-8859-1?Q?Syrj=E4l=E4?= , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Noralf =?iso-8859-1?Q?Tr=F8nnes?= , David Airlie References: <20161020143952.2538-1-tiwai@suse.de> <20161020145604.GW4329@intel.com> <20161021123032.GZ20761@phenom.ffwll.local> <20161021125728.GL25629@nuc-i3427.alporthouse.com> <20161021181903.GN20761@phenom.ffwll.local> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161021181903.GN20761@phenom.ffwll.local> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 736 Lines: 17 On Fri, Oct 21, 2016 at 08:19:03PM +0200, Daniel Vetter wrote: > On Fri, Oct 21, 2016 at 01:57:28PM +0100, Chris Wilson wrote: > > I think of a use for sending an empty clip: where you don't want to > > push any new pixel data, but you do want to be sure that the pipeline > > has been flushed. > > What exactly should an empty rectangle flush out? It's a bit unclear, but > for speed I guess drivers should be allowed to make dirty async ... No idea! I'm just speculating that I can see a use for a dirtyfb barrier even with an empty cliprect. Empty clips are a useful distinction elsewhere that I would suggest not forbidding them outright but defining their behaviour. -Chris -- Chris Wilson, Intel Open Source Technology Centre