On Thu, 2007-08-02 at 17:44 +0200, Jerome Glisse wrote: > > Btw i think that some GPU can wait on vblank using cmd ie you > don't need to ask the card to emit irq you just insert a cmd in > stream which stall further cmd execution until vblank happen, > this might be good for power consumption.
It's generally a bad idea because it prevents the GPU from doing anything else that could be done before vertical blank. > And will also be nice with app trying to avoid flickering/tearing > (mostly movie player). IME this can be achieved perfectly by scheduling the buffer swap to be executed from the interrupt handler, see the i915 DRM. > Concern is on application using things like GLX_SGI_video_sync > as without using IRQ we likely miss some vblank and thus can't > maintain accurate counter, thus maybe this fence vblank stuff > might just be an addition to vblank rework you already proposed > few weeks ago. Yes, while vblank fences would be a useful addition (without them, the above swap scheduling is prone to a race condition with multiple logical CPUs), I don't think they can be a replacement for the current vblank mechanisms, at least not all of them. -- Earthling Michel Dänzer | http://tungstengraphics.com Libre software enthusiast | Debian, X and DRI developer ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ -- _______________________________________________ Dri-devel mailing list Dri-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dri-devel
