drm/i915: Warn if stealing non pipe A/B power sequencer

There's no power sequencer on pipe C on VLV/CHV so scream a bit if we
try to steal one from pipes other than A and B.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 04d7bc730995..7df024c63bff 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -2691,6 +2691,9 @@ 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;
+
         list_for_each_entry(encoder, &dev->mode_config.encoder_list,
                             base.head) {
                 struct intel_dp *intel_dp;