[PATCH v2 3/7] drm/i915/display: Move vblank put until after critical section

[Maarten Lankhorst <dev@lankhorst.se>]

drm_crtc_vblank_put may take some locks, this should probably
not be the first thing we do after entering the time sensitive
part.

A better place is after programming is completed. Add a flag
to put the vblank after completion.

In the case of drm_vblank_work_schedule, we may not even need
to disable the vblank interrupt any more if it takes its own
reference.

Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>
---
 drivers/gpu/drm/i915/display/intel_cursor.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_cursor.c b/drivers/gpu/drm/i915/display/intel_cursor.c
index 7aa14348aa6d4..6b3bc8d94e51a 100644
--- a/drivers/gpu/drm/i915/display/intel_cursor.c
+++ b/drivers/gpu/drm/i915/display/intel_cursor.c
@@ -816,6 +816,7 @@ intel_legacy_cursor_update(struct drm_plane *_plane,
 		to_intel_crtc_state(crtc->base.state);
 	struct intel_crtc_state *new_crtc_state;
 	struct intel_vblank_evade_ctx evade;
+	bool has_vblank = false;
 	int ret;
 
 	/*
@@ -913,6 +914,8 @@ intel_legacy_cursor_update(struct drm_plane *_plane,
 	intel_psr_lock(crtc_state);
 
 	if (!drm_WARN_ON(display->drm, drm_crtc_vblank_get(&crtc->base))) {
+		has_vblank = true;
+
 		/*
 		 * TODO: maybe check if we're still in PSR
 		 * and skip the vblank evasion entirely?
@@ -922,8 +925,6 @@ intel_legacy_cursor_update(struct drm_plane *_plane,
 		local_irq_disable();
 
 		intel_vblank_evade(&evade);
-
-		drm_crtc_vblank_put(&crtc->base);
 	} else {
 		local_irq_disable();
 	}
@@ -939,6 +940,9 @@ intel_legacy_cursor_update(struct drm_plane *_plane,
 
 	intel_psr_unlock(crtc_state);
 
+	if (has_vblank)
+		drm_crtc_vblank_put(&crtc->base);
+
 	if (old_plane_state->ggtt_vma != new_plane_state->ggtt_vma) {
 		drm_vblank_work_init(&old_plane_state->unpin_work, &crtc->base,
 				     intel_cursor_unpin_work);
-- 
2.51.0