[PATCH 2/6] drm/i915: Move drm_crtc_vblank_get out of disabled pre-emption area.

[Rodrigo Vivi]

drm_crtc_vblank_get call the drm_vblank_prepare that will be used soon
to control power saving states or anything else that needs a mutex
before the vblank happens.

local_irq_disable disables kernel preemption so we won't be able
to use mutex inside drm_crtc_vblank_get. For this reason we need
to move the drm_crtc_vblank_get a little up before disabling the
interruptions.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
---
 drivers/gpu/drm/i915/intel_sprite.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index 0de935a..d8bc27c 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -94,14 +94,14 @@ void intel_pipe_update_start(struct intel_crtc *crtc)
 	min = vblank_start - usecs_to_scanlines(adjusted_mode, 100);
 	max = vblank_start - 1;
 
-	local_irq_disable();
-
 	if (min <= 0 || max <= 0)
 		return;
 
 	if (WARN_ON(drm_crtc_vblank_get(&crtc->base)))
 		return;
 
+	local_irq_disable();
+
 	crtc->debug.min_vbl = min;
 	crtc->debug.max_vbl = max;
 	trace_i915_pipe_update_start(crtc);
@@ -166,6 +166,8 @@ void intel_pipe_update_end(struct intel_crtc *crtc, struct intel_flip_work *work
 
 	trace_i915_pipe_update_end(crtc, end_vbl_count, scanline_end);
 
+	local_irq_enable();
+
 	/* We're still in the vblank-evade critical section, this can't race.
 	 * Would be slightly nice to just grab the vblank count and arm the
 	 * event outside of the critical section - the spinlock might spin for a
@@ -180,8 +182,6 @@ void intel_pipe_update_end(struct intel_crtc *crtc, struct intel_flip_work *work
 		crtc->base.state->event = NULL;
 	}
 
-	local_irq_enable();
-
 	if (crtc->debug.start_vbl_count &&
 	    crtc->debug.start_vbl_count != end_vbl_count) {
 		DRM_ERROR("Atomic update failure on pipe %c (start=%u end=%u) time %lld us, min %d, max %d, scanline start %d, end %d\n",
-- 
2.4.3