Re: [PATCH] drm/rockchip: Return -EBUSY if there's already a pending flip event v3

Hi Tomeu,

On 5 April 2016 at 16:07, Tomeu Vizoso tomeu.vizoso@collabora.com wrote:

On 4 April 2016 at 17:44, Daniel Stone daniel@fooishbar.org wrote:

...

On 4 April 2016 at 14:55, Tomeu Vizoso tomeu.vizoso@collabora.com wrote:

...

•   if (async) {
  

•           for_each_crtc_in_state(state, crtc, crtc_state, i) {
  

•                   if (crtc->state->event ||
  

•                       rockchip_drm_crtc_has_pending_event(crtc)) {
  

•                           return -EBUSY;
  

•                   }
  

•           }
  

•   }
  

Hmmm ...

Doesn't this trigger before the VOP atomic_begin() helper, meaning that anything with an event set will trigger the check? Seems like it should be && rather than ||.

So, these are the two cases that this code aims to handle:

1. A previous request with an event set hasn't progressed to

atomic_begin yet, so the event field in drm_crtc_state (at this point, the old state) is still populated but vop->event still isn't.

Ah right, this was what I was missing: the async (non-blocking) implementation. Sounds good to me then.

Cheers, Daniel