Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755481AbcC1WOO (ORCPT ); Mon, 28 Mar 2016 18:14:14 -0400 Received: from gloria.sntech.de ([95.129.55.99]:58730 "EHLO gloria.sntech.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752548AbcC1WOL convert rfc822-to-8bit (ORCPT ); Mon, 28 Mar 2016 18:14:11 -0400 From: Heiko =?ISO-8859-1?Q?St=FCbner?= To: Emil Velikov Cc: Yakir Yang , David Airlie , Mark Yao , Joonyoung Shim , Kumar Gala , Ian Campbell , Rob Herring , Pawel Moll , Russell King , devicetree , linux-kernel@vger.kernel.org, ML dri-devel , linux-rockchip , LAKML Subject: Re: [RFC PATCH v1 0/4] Add Rockchip RGA support Date: Tue, 29 Mar 2016 00:13:55 +0200 Message-ID: <17189219.y56YqHz6yR@diego> User-Agent: KMail/4.14.10 (Linux/4.4.0-1-amd64; KDE/4.14.14; x86_64; ; ) In-Reply-To: References: <1458552518-25527-1-git-send-email-ykk@rock-chips.com> <1571169.Hy8an0n7lM@diego> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT Content-Type: text/plain; charset="iso-8859-1" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7121 Lines: 160 Am Montag, 28. M?rz 2016, 23:07:59 schrieb Emil Velikov: > On 28 March 2016 at 22:46, Heiko St?bner wrote: > > Am Montag, 28. M?rz 2016, 22:35:36 schrieb Emil Velikov: > >> On 28 March 2016 at 19:44, Heiko St?bner wrote: > >> > Am Montag, 28. M?rz 2016, 13:21:02 schrieb Emil Velikov: > >> >> On 22 March 2016 at 00:42, Heiko Stuebner wrote: > >> >> > Hi Yakir, > >> >> > > >> >> > Am Montag, 21. M?rz 2016, 20:17:46 schrieb Yakir Yang: > >> >> >> On 03/21/2016 07:29 PM, Heiko St?bner wrote: > >> >> >> > Am Montag, 21. M?rz 2016, 17:28:38 schrieb Yakir Yang: > >> >> >> >> This patch set would add the RGA direct rendering based 2d > >> >> >> >> graphics > >> >> >> >> acceleration module. > >> >> >> > > >> >> >> > very cool to see that. > >> >> >> > >> >> >> ;) > >> >> >> > >> >> >> >> This patch set is based on git repository below: > >> >> >> >> git://people.freedesktop.org/~airlied/linux drm-next > >> >> >> >> commit id: 568d7c764ae01f3706085ac8f0d8a8ac7e826bd7 > >> >> >> >> > >> >> >> >> And the RGA driver is based on Exynos G2D driver, it only > >> >> >> >> manages > >> >> >> >> the > >> >> >> >> command lists received from user, so user should make the > >> >> >> >> command > >> >> >> >> list > >> >> >> >> to data and registers needed by operation to use. > >> >> >> >> > >> >> >> >> I have prepared an userspace demo application for testing: > >> >> >> >> https://github.com/yakir-Yang/libdrm-rockchip > >> >> >> >> > >> >> >> >> That is a rockchip libdrm library, and I have write a simple > >> >> >> >> test > >> >> >> >> case > >> >> >> >> "rockchip_rga_test" that would test the below RGA features: > >> >> >> >> - solid > >> >> >> >> - copy > >> >> >> >> - rotation > >> >> >> >> - flip > >> >> >> >> - window clip > >> >> >> >> - dithering > >> >> >> > > >> >> >> > Did you submit your libdrm changes as well? > >> >> >> > > >> >> >> > Userspace-interfaces need to be stable so the other side must > >> >> >> > also > >> >> >> > get > >> >> >> > accepted - even before the kernel change if I remember correctly. > >> >> >> > >> >> >> Got it, and I just saw exynos_fimg2d already landed at mainline > >> >> >> libdrm. > >> >> >> But I don't find the way to submit patches to libdrm, would you > >> >> >> like > >> >> >> share some helps here ;) > >> >> > > >> >> > Looking at the libdrm sources on cgit.freedesktop.org, I did not > >> >> > find > >> >> > any > >> >> > specific manual on submitting patches. > >> >> > > >> >> > But looking at the dri-list archive, dri-devel@lists.freedesktop.org > >> >> > is > >> >> > the > >> >> > right list and looking at the libdrm history it looks like Emil > >> >> > Velikov > >> >> > seems to be doing maintenance-stuff in > >> >> > libdrm. > >> >> > And as a 3rd recipient, please also include the linux-rockchip list. > >> >> > > >> >> > @Emil, please shout if I read that wrong :-) > >> >> > >> >> You got it spot on Heiko. There are a few notes though... > >> >> > >> >> As one reuses the existing hardware/IP block, it would be better to > >> >> avoid copy/pasting code around. > >> >> > >> >> Namely: > >> >> - (if possible) factor out the exynos g2d kernel functionality to a > >> >> > >> >> separate kernel module and wire up the rockhip (via dt ?) to use it > >> >> > >> >> - factor out the g2d specifics out of exynos_drm.h (into > >> >> > >> >> exynos_g2d_drm.h perhaps ?) and make sure exynos_drm.h includes the > >> >> new header > >> > > >> > I think the IP blocks themself are quite different between Rockchip's > >> > RGA > >> > and Samsung's g2d and I guess the similarities are more along the lines > >> > on how that gets integrated into the respective drm driver and > >> > userspace. > >> > >> In this case, the exynos_g2d_drm.h seems like a good idea. As I'm > >> obviously biased, it's better to check how others feel on the topic. > >> > >> >> - if neither of these are possible, then please ensure that the new > >> >> > >> >> header uses correct types (see the docs [1]), use MIT/X11 license (if > >> >> possible) and link where upstream userspace is happy with the > >> >> interface (ideally more than a simple test app like libdrm) > >> >> These might sound like an overkill, although getting UAPI right and > >> >> maintaining it forever forces us to do so. > >> > > >> > As for a real-world usecase, maybe the armsoc xserver might be somewhat > >> > easy to use. While the core changes I did are in the core project > >> > already, I'm still keeping the actual Rockchip support separate [0] due > >> > to the not-yet- resolved create_gem ioctl. > >> > > >> > Anyway, the armsoc xserver has some exa implementation hooks were I > >> > guess > >> > it might be relatively easy to hook up soc-specific things. > >> > >> Ouch the armsoc ddx... Last time I've checked it felt like a place > >> where everyone is doing his own thing, with no actual reviews and/or > >> maintainer. > > > > The development rate is pretty low and maintainership is unclear but the > > per- soc voodoo is quite limited to the GEM-creation and everything else > > seems somewhat nice when compared for example to the older versions of > > the ddx.> > >> Iirc most/all of it's functionality was achievable with > >> modesetting ddx (with or without glamor) ? I take it that things have > >> changed and/or I misunderstood something ? > > > > I don't really understand that whole stack or how xservers work on a whole > > ;-) I was merely able to make the _binary_ mali-driver work with this one > > and remembered that there were hooks for future per-soc exa functions. > > > > I guess for that glamor thing you'd need an actual gpu driver and not that > > libGL-override voodoo those crazy binary drivers do. > > > > At least the modesetting ddx didn't like mali-binary-driver. > > A quick rundown of the whole thing (simplified and maybe slightly off) > - the modesetting DDX (merged in xserver for a few releases now), > relies on GBM for buffer management and GL{,ES} for acceleration. On > the KMS side it's as generic as any other driver should be. > > I'm not sure how well modesetting works without gbm, but it should be > able to build at least. About getting it (or others) to work with > binary blobs... I guess you know what my and others' view is. Place > the fact that one tries to upstream a kernel interface which, > indirectly, interacts with such a module makes things even more ... > lovely. > > Sorry to be the bearer of bad news. If you have other ideas or others > feels like I'm overly dramatic let me know, please. I have the feeling we're going quite a bit off-topic right now :-) . The binary-driver-crazyness, hasn't really anything to do with Yakir's support for the RGA (which is about raster-graphics-acceleration, so 2d stuff). And me mentioning the armsoc-ddx was merely a means to allow some sort of different userspace user, as requested in your original mail ;-) . Maybe you know a better use-case on where to demonstrate the viability of the userspace API for it as originally requested.