From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753978AbdBVHFt (ORCPT ); Wed, 22 Feb 2017 02:05:49 -0500 Received: from mail.netline.ch ([148.251.143.178]:34918 "EHLO netline-mail3.netline.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751192AbdBVHFl (ORCPT ); Wed, 22 Feb 2017 02:05:41 -0500 Subject: Re: [PATCH v3 2/2] drm/fb-helper: implement ioctl FBIO_WAITFORVSYNC To: Stefan Lengfeld , Maxime Ripard Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Daniel Vetter References: <20170221100059.GD17643@sill.h.stcim.de> From: =?UTF-8?Q?Michel_D=c3=a4nzer?= Message-ID: <29b6baba-c83b-7591-f2e5-0fb0de609857@daenzer.net> Date: Wed, 22 Feb 2017 16:05:31 +0900 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.6.0 MIME-Version: 1.0 In-Reply-To: <20170221100059.GD17643@sill.h.stcim.de> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 21/02/17 07:00 PM, Stefan Lengfeld wrote: > > 2/ Wait for a single vsync event on all active crtcs as Ville Syrjälä > described here [2] in the optimal implementation. FWIW, this seems like a bad idea, since with multiple active CRTCs it would make it essentially random at which intervals the ioctl returns, and which CRTCs are in vertical blank when it does. So it would be useless for both timing and tearing prevention purposes, i.e. more or less completely useless. -- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Mesa and X developer From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?Q?Michel_D=c3=a4nzer?= Subject: Re: [PATCH v3 2/2] drm/fb-helper: implement ioctl FBIO_WAITFORVSYNC Date: Wed, 22 Feb 2017 16:05:31 +0900 Message-ID: <29b6baba-c83b-7591-f2e5-0fb0de609857@daenzer.net> References: <20170221100059.GD17643@sill.h.stcim.de> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from netline-mail3.netline.ch (mail.netline.ch [148.251.143.178]) by gabe.freedesktop.org (Postfix) with ESMTP id E65706E740 for ; Wed, 22 Feb 2017 07:05:38 +0000 (UTC) In-Reply-To: <20170221100059.GD17643@sill.h.stcim.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Stefan Lengfeld , Maxime Ripard Cc: Daniel Vetter , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org T24gMjEvMDIvMTcgMDc6MDAgUE0sIFN0ZWZhbiBMZW5nZmVsZCB3cm90ZToKPiAKPiAyLyBXYWl0 IGZvciBhIHNpbmdsZSB2c3luYyBldmVudCBvbiBhbGwgYWN0aXZlIGNydGNzIGFzIFZpbGxlIFN5 cmrDpGzDpCAKPiAgICBkZXNjcmliZWQgaGVyZSBbMl0gaW4gdGhlIG9wdGltYWwgaW1wbGVtZW50 YXRpb24uCgpGV0lXLCB0aGlzIHNlZW1zIGxpa2UgYSBiYWQgaWRlYSwgc2luY2Ugd2l0aCBtdWx0 aXBsZSBhY3RpdmUgQ1JUQ3MgaXQKd291bGQgbWFrZSBpdCBlc3NlbnRpYWxseSByYW5kb20gYXQg d2hpY2ggaW50ZXJ2YWxzIHRoZSBpb2N0bCByZXR1cm5zLAphbmQgd2hpY2ggQ1JUQ3MgYXJlIGlu IHZlcnRpY2FsIGJsYW5rIHdoZW4gaXQgZG9lcy4gU28gaXQgd291bGQgYmUKdXNlbGVzcyBmb3Ig Ym90aCB0aW1pbmcgYW5kIHRlYXJpbmcgcHJldmVudGlvbiBwdXJwb3NlcywgaS5lLiBtb3JlIG9y Cmxlc3MgY29tcGxldGVseSB1c2VsZXNzLgoKCi0tIApFYXJ0aGxpbmcgTWljaGVsIETDpG56ZXIg ICAgICAgICAgICAgICB8ICAgICAgICAgICAgICAgaHR0cDovL3d3dy5hbWQuY29tCkxpYnJlIHNv ZnR3YXJlIGVudGh1c2lhc3QgICAgICAgICAgICAgfCAgICAgICAgICAgICBNZXNhIGFuZCBYIGRl dmVsb3BlcgpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpk cmktZGV2ZWwgbWFpbGluZyBsaXN0CmRyaS1kZXZlbEBsaXN0cy5mcmVlZGVza3RvcC5vcmcKaHR0 cHM6Ly9saXN0cy5mcmVlZGVza3RvcC5vcmcvbWFpbG1hbi9saXN0aW5mby9kcmktZGV2ZWwK