On Thu, Apr 03, 2014 at 02:28:32PM +0530, Archit Taneja wrote: > On Wednesday 02 April 2014 06:41 PM, Rob Clark wrote: > >On Wed, Apr 2, 2014 at 5:52 AM, Archit Taneja <archit@xxxxxx> wrote: > >>Hi, > >> > >>I was trying to figure out how we are supposed to manage synchronization > >>between a mode_set and a page_flip called on a crtc. > >> > >>Say, if a mode_set is immediately followed by a page_flip. The driver can't > >>process the page_flip straight away since the hardware is still completing > >>the mode_set. > > > >I guess setcrtc is expected to be synchronous(ish).. so a lot of > >userspace won't expect the first pageflip to fail with -EBUSY. > > Okay, thanks. I guess having setcrtc synchronous isn't that bad. Yeah, atm I think the rules are that pageflip can only return -EBUSY if there's still a pageflip ongoing. Everything else is presumed to be at least implicitly ordered, so if your hw can do async modesets then you need to synchronize. Also if there's still a pageflip outstanding you need to wait for that to complete in your set_config callback first (usually in the set_base or the crtc->disable/prepare hooks when using the crtc helpers). -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
