From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Airlie Subject: Re: [RFC 0/4] Add NVIDIA Tegra DRM support Date: Thu, 19 Apr 2012 20:28:20 +0100 Message-ID: References: <1334146230-1795-1-git-send-email-thierry.reding@avionic-design.de> <20120419173537.GA7692@avionic-0098.adnet.avionic-design.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Return-path: In-Reply-To: <20120419173537.GA7692-RM9K5IK7kjIyiCvfTdI0JKcOhU4Rzj621B7CTYaBSLdn68oJJulU0Q@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Thierry Reding Cc: linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, 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 , Jon Mayo , Hiroshi Doyu List-Id: linux-tegra@vger.kernel.org On Thu, Apr 19, 2012 at 6:35 PM, Thierry Reding wrote: > Before posting the next round of patches I wanted to clarify whether we need > to take the Tegra driver through staging. Lucas brought this up referring to > previous experience with Nouveau where Linus used to complain that userspace > ABI was broken for non-staging drivers. I don't know how relevant that is > for Tegra. We could also keep it in drivers/gpu/drm and only add userspace > interfaces that we are sure are not going to change. Currently there isn't > isn't anything that could be easily broken as only some of the standard DRM > interfaces are supported anyway. > > Alternatively we could keep the driver in a separate tree until it becomes > mature enough. > > Any thoughts? It's probably okay to avoid staging if it doesn't add any userspace ioctls. A KMS driver that just supports the dumb ioctls so -modesetting works, would be the first thing to aim for I suppose, like how the exynos guys did it. Adding userspace interfaces is where you'll get into ABI guarantees etc, and these are normally required only for the accel engines. Dave.