From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1163742AbcG1DCH (ORCPT ); Wed, 27 Jul 2016 23:02:07 -0400 Received: from regular1.263xmail.com ([211.150.99.131]:39752 "EHLO regular1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1163226AbcG1DBV (ORCPT ); Wed, 27 Jul 2016 23:01:21 -0400 X-263anti-spam: KSV:0;BIG:0;ABS:1;DNS:0;ATT:0;SPF:S; X-MAIL-GRAY: 0 X-MAIL-DELIVERY: 1 X-KSVirus-check: 0 X-ABS-CHECKED: 1 X-SKE-CHECKED: 1 X-ADDR-CHECKED: 0 X-RL-SENDER: mark.yao@rock-chips.com X-FST-TO: linux-kernel@vger.kernel.org X-SENDER-IP: 58.22.7.114 X-LOGIN-NAME: mark.yao@rock-chips.com X-UNIQUE-TAG: <940e969f3d8c070a69791dbce31e314b> X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 Subject: Re: [PATCH 1/3] drm: introduce share plane To: David Airlie , Heiko Stuebner , dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org References: <1469519194-23133-1-git-send-email-mark.yao@rock-chips.com> <20160726082635.GA31475@phenom.ffwll.local> <579732B2.80600@rock-chips.com> From: Mark yao Message-ID: <57997570.5070806@rock-chips.com> Date: Thu, 28 Jul 2016 11:01:04 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <579732B2.80600@rock-chips.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Any ideas for the share planes? This function is important for our series of vop full design. The series of vop is: IP version chipname 3.1 rk3288 3.2 rk3368 3.4 rk3366 3.5 rk3399 big 3.6 rk3399 lit 3.7 rk322x example on rk3288: if not support share plane, each vop only support four planes, but if support this function, each vop can support ten planes. On 2016年07月26日 17:51, Mark yao wrote: > On 2016年07月26日 16:26, Daniel Vetter wrote: >> On Tue, Jul 26, 2016 at 03:46:32PM +0800, Mark Yao wrote: >>> >What is share plane: >>> >Plane hardware only be used when the display scanout run into plane >>> active >>> >scanout, that means we can reuse the plane hardware resources on plane >>> >non-active scanout. >>> > >>> > -------------------------------------------------- >>> > | scanout | >>> > | ------------------ | >>> > | | parent plane | | >>> > | | active scanout | | >>> > | | | ----------------- | >>> > | ------------------ | share plane 1 | | >>> > | ----------------- |active scanout | | >>> > | | share plane 0 | | | | >>> > | |active scanout | ----------------- | >>> > | | | | >>> > | ----------------- | >>> > -------------------------------------------------- >>> >One plane hardware can be reuse for multi-planes, we assume the first >>> >plane is parent plane, other planes share the resource with first one. >>> > parent plane >>> > |---share plane 0 >>> > |---share plane 1 >>> > ... >>> > >>> >Because resource share, There are some limit on share plane: one group >>> >of share planes need use same zpos, can not overlap, etc. >>> > >>> >We assume share plane is a universal plane with some limit flags. >>> >people who use the share plane need know the limit, should call the >>> ioctl >>> >DRM_CLIENT_CAP_SHARE_PLANES, and judge the planes limit before use it. >>> > >>> >A group of share planes would has same shard id, so userspace can >>> >group them, judge share plane's limit. >>> > >>> >Signed-off-by: Mark Yao >> This seems extremely hw specific, why exactly do we need to add a new >> relationship on planes? What does this buy on_other_ drivers? > Yes, now it's plane hardware specific, maybe others have same design, > because this design > would save hardware resource to support multi-planes. > >> Imo this should be solved by virtualizing planes in the driver. Start >> out >> by assigning planes, and if you can reuse one for sharing then do that, >> otherwise allocate a new one. If there's not enough real planes, fail >> the >> atomic_check. > I think that is too complex, trying with atomic_check I think it's not > a good idea, userspace try planes every commit would be a heavy work. > > Userspace need know all planes relationship, group them, some display > windows can put together, some can't, > too many permutation and combination, I think can't just commit with try. > > example: > userspace: > windows 1: pos(0, 0) size(1024, 100) > windows 2: pos(0, 50) size(400, 500) > windows 3: pos(0, 200) size(800, 300) > > drm plane resources: > plane 0 and plane 1 is a group of share planes > plane 2 is common plane. > > if userspace know the relationship, then they can assign windows 1 and > window 3 to plane0 and plane 1. that would be success. > but if they don't know, assign window 1/2 to plane 0/1, failed, assign > window 2/3 to plane 0/1, failed. mostly would get failed. > >> >> This seems way to hw specific to be useful as a generic concept. > > We want to change the drm_mode_getplane_res behavior, if userspace > call DRM_CLIENT_CAP_SHARE_PLANES, that means userspace know hardware > limit, > then we return full planes support to userspace, if don't, just make a > group of share planes as one plane. > this work is on generic place. > >> -Daniel >> >> > -- Ｍark Yao