[Intel-gfx] [PATCH] drm/i915: Avoid spurious WARNs about the wrong pipe in the PPS code

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

Until recently vlv_steal_power_sequencer() wasn't being called for
normal DP ports, and hence it could assert that it should only be
called for pipe A and B (since pipe C doesn't support eDP). However
that changed when we started to consider normal DP ports as well when
choosing a PPS. So we will now get spurious warnings when
vlv_steal_power_sequencer() does get called for pipe C. Avoid this by
moving the WARN down into vlv_detach_power_sequencer() where this
assertion should still hold.

Cc: Imre Deak <imre.deak at intel.com>
Cc: stable at vger.kernel.org
Fixes: 9f2bdb006a7e ("drm/i915: Prevent PPS stealing from a normal DP port on VLV/CHV")
References: https://bugs.freedesktop.org/show_bug.cgi?id=95287
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_dp.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 0f14e97e519b..2395046e19ce 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -2905,6 +2905,9 @@ static void vlv_detach_power_sequencer(struct intel_dp *intel_dp)
 
 	WARN_ON(intel_dp->active_pipe != INVALID_PIPE);
 
+	if (WARN_ON(pipe != PIPE_A && pipe != PIPE_B))
+		return;
+
 	edp_panel_vdd_off_sync(intel_dp);
 
 	/*
@@ -2932,9 +2935,6 @@ static void vlv_steal_power_sequencer(struct drm_device *dev,
 
 	lockdep_assert_held(&dev_priv->pps_mutex);
 
-	if (WARN_ON(pipe != PIPE_A && pipe != PIPE_B))
-		return;
-
 	for_each_intel_encoder(dev, encoder) {
 		struct intel_dp *intel_dp;
 		enum port port;
-- 
2.10.2