On Thu, 26 Jul 2012 21:30:19 +0100, Chris Wilson <chris at chris-wilson.co.uk> wrote: > In order for the Display Engine to send messages to the Render Engine, > that event must be unmasked in the Display Engine Render Response Mask > Register (DERRMR). By default all events are masked to prevent unwanted > messages to conserve power, and it is strongly recommended that only > single events be unmasked at any time. So in order to pipeline the > register writes around individual batchbuffers, userspace must notify > the kernel when it requires a vblank event, this patch implements an > interface to do so with an single (pipe, event) request through the > execbuffer flags. > > Note that another workaround is required for IVB, in that we must also > prevent RC6 sleeps whilst waiting upon an event. To do that we also > pipeline a forcewake into the second MT slot. Anyone have any criticisms for this patch? -Chris -- Chris Wilson, Intel Open Source Technology Centre
