[Intel-gfx] [PATCH 19/38] drm/hisilicon: Implement some semblance of vblank event handling

[Xinliang Liu]

On 21 June 2016 at 15:19, Daniel Vetter <daniel at ffwll.ch> wrote:
> On Tue, Jun 21, 2016 at 3:32 AM, Xinliang Liu <xinliang.liu at linaro.org> wrote:
>> My understanding is that drm_crtc_arm_vblank_event work together with
>> drm_crtc_handle_vblank (called in vblank interrupt).
>> Arm the event first in somewhere(like atomic_begin/flush) and then
>> send it out throuth drm_crtc_handle_vblank in vblank interrupt.
>> In the other way, drm_crtc_send_vblank_event work together with flip
>> interrupt. That's means event will be sent in flip interrupt
>> immediately.
>> Is this right?
>
> First part is right. Second part about drm_crtc_send_vblank event just
> sends out the vblank directly (using the last recorded vblank). The
> vblank subsystem doesn't itself interact with any interrupt.
>
> Note that there's kerneldoc for all of this. Please make sure it does
> describe things sufficiently well, and if not please send in patches
> to improve them.

Ok, I will take a look at the doc.

Thanks,
-xinliang

> -Daniel
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch