Hi,
On 6 August 2015 at 13:49, Daniel Vetter daniel@ffwll.ch wrote:
On Thu, Aug 06, 2015 at 01:19:35PM +0200, Maarten Lankhorst wrote:
Op 06-08-15 om 11:47 schreef Daniel Stone:
On 30 July 2015 at 08:03, Maarten Lankhorst maarten.lankhorst@linux.intel.com wrote:
if (!state->active && state->event) {DRM_DEBUG_ATOMIC("[CRTC:%d] requesting event and not active\n",crtc->base.id);return -EINVAL;}Hmm, even if disabling? Maybe (!crtc->state->active && !state->active) && state->event.
How do you want to send a vblank event after disabling?
The event would be when we stop scanning out, but yeah that's a bit a tricky one. I guess for now (until we have someone who needs this) we could just merge Maarten's patch as the easier thing to do right now? Maybe with a small code comment that this is intentional?
Exactly that. Surely this (when the CRTC actually goes dark) is something we already know? Assuming you don't have atomic_disable / instant-scanout-stop, and have to wait until the next vblank to kill it, then how does this work? - create FB - assign FB to plane on CRTC - unreference FB such that plane holds the last remaining reference - set plane->fb == NULL + crtc->active = 0, i.e. SetCrtc(NULL, 0, 0, 0, 0, ...)
You can't immediately unpin/destroy the FB since you might still be mid-scanout. So you already need to defer this, and that would be the point at which you stop scanout. In a lot of hardware, this is just another latched register which takes effect on the next vblank, for which you still catch an IRQ - at which point you send the event. If you actually have atomic_disable hardware that stops scanout immediately, you can just send the event immediately.
What am I missing?
Cheers, Daniel