[Intel-gfx] [PATCH 4/4] drm/i915: WARN if PLL ref/unref got messed up

[Ville Syrjala]

From: Ville Syrjälä <ville.syrj...@linux.intel.com>

Spew a WARN if we try to ref/unref the same DPLL multiple
times for the same pipe.

Signed-off-by: Ville Syrjälä <ville.syrj...@linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_dpll_mgr.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dpll_mgr.c 
b/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
index c21818cb6fe2..2a6ef1398c84 100644
--- a/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
+++ b/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
@@ -384,6 +384,8 @@ intel_reference_shared_dpll(struct intel_atomic_state 
*state,
        if (shared_dpll[id].pipe_mask == 0)
                shared_dpll[id].hw_state = *pll_state;
 
+       drm_WARN_ON(&i915->drm, (shared_dpll[id].pipe_mask & BIT(crtc->pipe)) 
!= 0);
+
        shared_dpll[id].pipe_mask |= BIT(crtc->pipe);
 
        drm_dbg(&i915->drm, "[CRTC:%d:%s] reserving %s\n",
@@ -396,10 +398,13 @@ static void intel_unreference_shared_dpll(struct 
intel_atomic_state *state,
 {
        struct drm_i915_private *i915 = to_i915(state->base.dev);
        struct intel_shared_dpll_state *shared_dpll;
+       const enum intel_dpll_id id = pll->info->id;
 
        shared_dpll = intel_atomic_get_shared_dpll_state(&state->base);
 
-       shared_dpll[pll->info->id].pipe_mask &= ~BIT(crtc->pipe);
+       drm_WARN_ON(&i915->drm, (shared_dpll[id].pipe_mask & BIT(crtc->pipe)) 
== 0);
+
+       shared_dpll[id].pipe_mask &= ~BIT(crtc->pipe);
 
        drm_dbg(&i915->drm, "[CRTC:%d:%s] releasing %s\n",
                crtc->base.base.id, crtc->base.name, pll->info->name);
-- 
2.35.1