From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by yocto-www.yoctoproject.org (Postfix, from userid 118) id 4F091E00853; Tue, 23 Sep 2014 11:46:08 -0700 (PDT) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on yocto-www.yoctoproject.org X-Spam-Level: X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.1 X-Spam-HAM-Report: * -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low * trust * [209.85.192.169 listed in list.dnswl.org] Received: from mail-pd0-f169.google.com (mail-pd0-f169.google.com [209.85.192.169]) by yocto-www.yoctoproject.org (Postfix) with ESMTP id 73C77E00786 for ; Tue, 23 Sep 2014 11:46:05 -0700 (PDT) Received: by mail-pd0-f169.google.com with SMTP id fp1so2864986pdb.28 for ; Tue, 23 Sep 2014 11:46:04 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:message-id:date:from:user-agent:mime-version:to :cc:subject:references:in-reply-to:content-type :content-transfer-encoding; bh=dY3XMNXlRpGwjrW2ORZcUgGVIkZRpL8JDY3yXMtyMK0=; b=TT5YzOIRhDJDUg9L/kKfSY7FEvcjYEsQr3EaO5qLV3zlzUnR3viPZGQmjb8w4csNZC +NaERZJYBWA3u2ywdS3KAt4OtRQXdN/7CTPVbfwiattqb6TBCPQzkH28zO5s2n0BU6N+ K20vEeQRwJHlAiel9Vij7vYytGYoTviU9FNcwVhk1kVlb3qsAeXfZDrmPKUUmKNnLdOw RJuTPPX//fOO0SyGCfWtkOo4mdSVGLXh3TrCf4BpX8rZ4pcHceyVavbvR6RMkyBjde3f 6H6s1yzPI4MeggIrwvwHf/6/P4YUVgV7u/A/QWMljPCOdbljsLRAWGGuEm1QofuaOP4b A+6g== X-Gm-Message-State: ALoCoQkVpGa7vREZ2oUT8UjC3wOtWtqKQCPQW+DNTFWywrx3gNw1mnhyRhzNKHe5gijbjtVI3z8k X-Received: by 10.67.15.172 with SMTP id fp12mr2387056pad.4.1411497964606; Tue, 23 Sep 2014 11:46:04 -0700 (PDT) Received: from [29.6.1.8] ([63.226.49.26]) by mx.google.com with ESMTPSA id qp9sm12710172pbc.31.2014.09.23.11.46.02 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 23 Sep 2014 11:46:03 -0700 (PDT) Message-ID: <5421BFE9.2010200@boundarydevices.com> Date: Tue, 23 Sep 2014 11:46:01 -0700 From: Eric Nelson User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.1 MIME-Version: 1.0 To: Carlos Rafael Giani , Prabhu S References: <020a01cfd6e7$40280df0$c07829d0$@tekmagic.net> <3A8E1855-6288-49E4-9D89-7B8C19B38E1E@tekmagic.net> <54217CF4.8090004@pseudoterminal.org> <02c301cfd73b$22224fb0$6666ef10$@tekmagic.net> <542189E0.9080105@pseudoterminal.org> <5421B365.9010409@pseudoterminal.org> In-Reply-To: <5421B365.9010409@pseudoterminal.org> Cc: "meta-freescale@yoctoproject.org" Subject: Re: Any hope of vblank-synchronized rendering (from vivante) on i.MX6 soon? X-BeenThere: meta-freescale@yoctoproject.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Usage and development list for the meta-fsl-* layers List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 23 Sep 2014 18:46:08 -0000 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Hi Carlos, On 09/23/2014 10:52 AM, Carlos Rafael Giani wrote: > > I wonder why it is single buffered. is it because of the memory > consumption for a second buffer? The buffers could be flipped, > eliminating any need for blits, so the memory bandwidth should not be an > issue. > There is a memory bandwidth implication. Assuming frame buffers A and B in a double-buffered system, rendering will occur into B while A is displayed, then the two will be swapped, such that B is displayed and A is the new rendering output. In order for apps to only update parts of their windows, any "dirty" blocks need to be copied from B to A in the process of the flip. > On 2014-09-23 18:48, Prabhu S wrote: >> i.MX6 X11 EGL is single buffered and there is no support for VSYNC. >> The tearing with X11 is a known issue. We did investigate to fix this, >> but the solution becomes too hacky and cannot be used in production >> systems. >> >> We are adding VSYNC support in Wayland. eglSwapInterval will be >> supported for FBDEV and Wayland backends in the upcoming release(in >> january). So Ozone-wayland can take advantage of this. >> ?? This is already supported in Wayland, though it is controlled by an environment variable. You can see it in action by watching /sys/class/graphics/fb0/pan. Regards, Eric