On Thu, 15 Jun 2017 16:30:58 -0700 Eric Anholt <eric@xxxxxxxxxx> wrote: > Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx> writes: > > > There are two problems related to VBLANK handling in the current CRTC > > driver: > > > > * VBLANK events are missed when the CRTC is being disabled because the > > driver does not wait till the end of the frame before stopping the > > HVS and PV blocks. In this case, we should explicitly issue a VBLANK > > event if there's one waiting > > * when we are enabling a CRTC, drm_crtc_vblank_get() is called before > > drm_crtc_vblank_on(), which is not supposed to happen (hence the > > WARN_ON() in the code). To solve the problem, we delay the 'update > > display list' operation after the CRTC is actually enabled. > > Does drm_crtc_vblank_get() actually fail when drm_crtc_vblank_on() > hasn't been called? The code is a bit twisty, but it looked like we > would track the get refcount and then turn on the interrupt once > drm_crtc_vblank_on() was called. I thought I had faced the WARN_ON() backtrace while developing the TXP block, but I can't reproduce it (even after reverting these changes), so it was probably caused by something else. > > The first change of the two seems straightforward and good, though (and > possible to separate, right?). I'll prepare a new patch containing only the first change. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
