The real question is what you want to be controlling. The two factors that we can actually influence are voltage and frequency - and on some cards we're limited to frequency. Everything else is then constrained by that choice. So the only thing that it makes sense to expose to userspace here is the frequency. As others have suggested, policy is probably best described in terms of either performance (fixed maximum frequency) or powersave (ondemand frequency shifting).
That's not to say that there aren't other constraints people may want to impose, but they're orthogonal. A user may want to stop their GPU from running at more than a certain temperature. That can be achieved by leaving this interface as is, but hooking it into the kernel thermal zone code. The user can then set a temperature limit and the kernel will automatically slow the chip down whenever it gets near that temperature. Since this is effectively a proxy for fan speed, that also gets catered for. So I think a general policy knob (like scaling_cur_governor in cpufreq) ought to be sufficient here, possibly along with an indication of the instantaneous frequency because some people seem to like that kind of thing. Anything else sounds like overengineering. -- Matthew Garrett | mj...@srcf.ucam.org ------------------------------------------------------------------------------ This SF.Net email is sponsored by the Verizon Developer Community Take advantage of Verizon's best-in-class app development support A streamlined, 14 day to market process makes app distribution fast and easy Join now and get one step closer to millions of Verizon customers http://p.sf.net/sfu/verizon-dev2dev -- _______________________________________________ Dri-devel mailing list Dri-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dri-devel
