On 22.01.2013 21:59, Mario Kleiner wrote: > The current swap scheduling is based on having an accurate software > vblank counter. Atm. that counter is maintained in software, incremented > during vblank irq. At irq off -> on transition we need a hw counter to > reinitialize. And there is a timeout between dropping the last reference > to a counter via drm_vblank_put() and actually disabling the vblank irq. > If the timeout is long enough and a timing sensitive app is aware that > vblank counters may be inaccurate/unreliable over long time periods, it > can work around the problem. We have a hardware counter that can be used as VBLANK counter - host1x sync point register numbers 26 and 27. tegradrm already sets them up in dc init (DC_CMD_CONT_SYNCPT_VSYNC). Basic syncpt support (read, wait) is part of my patch set to implement 2D acceleration. Terje -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
