[Intel-gfx] [PATCH 1/6] drm/atomic: Use active instead of enable in wait_for_vblanks.

[Daniel Vetter]

On Thu, Dec 08, 2016 at 02:45:24PM +0100, Maarten Lankhorst wrote:
> When DPMS was introduced to atomic, vblanks only worked when the crtc
> was enabled and active. wait_for_vblanks were not converted to check for
> crtc_state->active, which may cause an attempt for vblank_get to fail.
> 
> This is probably harmless, but convert from enable to active anyway.
> 
> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> ---
>  drivers/gpu/drm/drm_atomic_helper.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> index 583f47f27b36..23767df72615 100644
> --- a/drivers/gpu/drm/drm_atomic_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_helper.c
> @@ -1117,7 +1117,7 @@ drm_atomic_helper_wait_for_vblanks(struct drm_device *dev,
>  		 * vblank wait) in the ->enable boolean. */
>  		old_crtc_state->enable = false;
>  
> -		if (!crtc->state->enable)
> +		if (!crtc->state->active)

Hm, with this change we /should/ be able to make the drm_crtc_vblank_get
call a few lines below WARN when it fails. Not doing that was only done at
first because there was no accurate active state tracking for the CRTC,
and since the vblank state should match active I've used that. Care for
that follow-up patch?

Applied this one here meanwhile.
-Daniel
>  			continue;
>  
>  		/* Legacy cursor ioctls are completely unsynced, and userspace
> -- 
> 2.7.4
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch