On Tue, Apr 17, 2012 at 08:34:11PM +0000, Lawrynowicz, Jacek wrote: > ARB_timer_query allows client read TIMESTAMP both asynchronously and synchronously. > The former can be implemented as you said but the latter requires support from the KMD. > This must be a simple MMIO read as this is the only way to report "current" GPU time. > Implementing synchronous TIMESTAMP query using pipe control would render the third example from ARB_timer_query spec useless. Ok, I've looked like a dofus again, but now I've read the spec and we indeed seem to need a synchronous readout of the TIMESTAMP register. I guess a new register will do, together with some fixed-point integer that tells userspace how to convert it to nanoseconds. -Daniel -- Daniel Vetter Mail: daniel at ffwll.ch Mobile: +41 (0)79 365 57 48
