From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lucas Stach Subject: Re: [RFC 0/4] Add NVIDIA Tegra DRM support Date: Fri, 20 Apr 2012 08:05:11 +0200 Message-ID: <1334901911.1361.11.camel@tellur> References: <1334146230-1795-1-git-send-email-thierry.reding@avionic-design.de> <20120419173537.GA7692@avionic-0098.adnet.avionic-design.de> <20120419204016.GA8954@avionic-0098.mockup.avionic-design.de> <4F907CBB.4080705@nvidia.com> <20120420050231.GA15313@avionic-0098.adnet.avionic-design.de> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20120420050231.GA15313-RM9K5IK7kjIyiCvfTdI0JKcOhU4Rzj621B7CTYaBSLdn68oJJulU0Q@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Thierry Reding Cc: Jon Mayo , Stephen Warren , Joerg Roedel , "devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org" , "dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org" , "iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org" , Colin Cross , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Hiroshi Doyu List-Id: linux-tegra@vger.kernel.org Am Freitag, den 20.04.2012, 07:02 +0200 schrieb Thierry Reding: > * Jon Mayo wrote: > > On 04/19/2012 01:40 PM, Thierry Reding wrote: > [...] > > >So would it be possible to get a basic dumb KMS driver into mainline > > >(non-staging) and phase in acceleration later on, with ABI guarantees? I > > >guess development can go on in separate trees until the ABI is stable and can > > >subsequently be ported to the mainline driver. > > > > > >Is that an acceptable approach? > > > > That certainly seems like the most reasonable approach to me. Get > > KMS only in first. It's a useful driver as-is, and has the lowest > > barrier to entry into upstream. > > > > Then later we can phase in enhancements. We certainly have plenty of > > places internally and externally to hash out acceleration > > interfaces, and come to some consensus at at later date (either on > > linux-tegra or direct email). > > Okay. Let's do that then. Yes, I think we should go the route that Jerome Glisse pointed out: get in a basic KMS driver first and hide any accel ioctl under a staging config option. > > > We have a lot of concerns here. What is best for X11, what is best > > for Android, how do we keep healthy open source implementations, and > > how does NVIDIA move forward with supporting new Tegra on an open > > source implementation. > > I think by supporting the DRM we can get pretty far for X11. Writing a Tegra- > specific driver based off xf86-video-modesetting can be done to use advanced > features if they can't be abstracted away properly. DRM also paves the way > for Wayland support. > > What I see as somewhat of a problem is how to get NVIDIA and the community to > work together (and work together well). We'll have to see how this works out, > but I'd hate to see more resources wasted because everybody starts doing > their own thing. I'm really interested how this turns out in the end. I hope we can get a somewhat stable cooperation between NVIDIA and the community, like AMD has established at the moment. > > > (My vote is NVIDIA starts using this DRM in-house and builds new > > extensions on top of it, sharing patches on LKML when the hardware is > > released) > > That sounds like a good plan. Ideally you should even share the patches as > soon as they're ready. That'll give viewers some head start and you can fix > the code even before the hardware is released. One thing I would like to have is upstream first. We have seen much Tegra development in both the nv-linux and chromium trees, but those things are going upstream extremely slowly. I can understand that this strategy was beneficial for a fast bring up of the new Tegra hardware, but the DRM driver shouldn't be time critical and so everything should be done to meet upstream quality from the start. -- Lucas