On Thu, Jan 31, 2013 at 3:06 AM, Mario Kleiner <mario.kleiner@xxxxxxxxxxxxxxxx> wrote: > At least AMD hw as of a while ago didn't, older intel hw didn't (afaik), and > NVidia i don't know. You'd also need hw vblank timestamps and counters > independent of page-flip completion to not regress existing important > functionality if you want to get rid of the irq based method. Intel hw has counters+timestamps for pageflips and vblanks, so you get the cake and eat it, too. I'm also aware of your stringent requirements wrt timestamps, so the recently pimped kms_flip test we have for drm/i915.ko checks vblank timestamps, pageflip timestamps and whether those don't get out of sync somehow in a rather anal way. Results thus far is that the current vblank stuff is (at least for intel) pretty horribly broken - QA reported random and sometimes not-so-random failures across all generations. So we still have plenty of fixing to do until we can get around to implement pageflip timestamping without the irq vblank running all the time. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch -- 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
