Hi Thomas, On Mon, Aug 31, 2009 at 11:34:00AM +0200, Thomas Hellström wrote: > Hi, > > Is there any way we can try and put together a generic drm interface for > this instead of an Intel-specific one? I've tried to make the ioctl somewhat generic. That's the reason for the generic buffer format flags (and the corresponding mapping to/from intel overlay formats in kernel and ddx). So when the radeon devs are interested in overlay support, there shouldn't be a big problem in distilling a common ioctl interface.
But I don't see the point in a generic ioctl, because there are quite a lot of hw specific restrictions (alignment, stride for all possible yuv formats, ...) which a generic userspace driver would not know. See intel_overlay_put_image in i915/intel_overlay.c for all the checks. A few of these tests are buffer format specific and can certainly be extracted and reused as helper functions, but besides that I don't see much code to share. Moreover we most likely still need a device specific ioctl to adjust color parameters (gamma, yuv->rbg mapping, ...). I also don't see any gain in adding overlay support to the generic struct drm_crtc because handling this crtc<->overlay relation is just a few lines in my code. So not many opportunities to share stuff. > Surely it will have a use for the Gallium Xorg state-tracker which is > intended to be a device-independent Xorg driver on top of KMS and > Gallium. At least for intel this does not make sense. Gallium is only supported for 915 and onwards. So is textured video. Which leaves us with 8xx class hw in need of overlay support but no way of gallium support (no shaders). Furthermore I don't think it's a good idea to spoil the shiny new X architecture with support for archaic hardware like overlays (which ruins every compositioned desktop experience). In conclusion I don't think a common ioctl is worth it. But sharing some code and infrastructure on the kernel side is certainly possible, if someone implements overlay support for another chipset. But I don't really count on that, because at least radeon has textured video for all it's chips. > /Thomas Yours, Daniel -- Daniel Vetter Mail: dan...@ffwll.ch Mobile: +41 (0)79 365 57 48 ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july -- _______________________________________________ Dri-devel mailing list Dri-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dri-devel
