Merge tag 'drm-intel-next-2015-03-13-merge' of git://anongit.freedesktop.org/drm-intel into drm-next

drm-intel-next-2015-03-13-rebased:
- EU count report param for gen9+ (Jeff McGee)
- piles of pll/wm/... fixes for chv, finally out of preliminary hw support
  (Ville, Vijay)
- gen9 rps support from Akash
- more work to move towards atomic from Matt, Ander and others
- runtime pm support for skl (Damien)
- edp1.4 intermediate link clock support (Sonika)
- use frontbuffer tracking for fbc (Paulo)
- remove ilk rc6 (John Harrison)
- a bunch of smaller things and fixes all over

Includes backmerge because git rerere couldn't keep up any more.

* tag 'drm-intel-next-2015-03-13-merge' of git://anongit.freedesktop.org/drm-intel: (366 commits)
  drm/i915: Make sure the primary plane is enabled before reading out the fb state
  drm/i915: Update DRIVER_DATE to 20150313
  drm/i915: Fix vmap_batch page iterator overrun
  drm/i915: Export total subslice and EU counts
  drm/i915: redefine WARN_ON_ONCE to include the condition
  drm/i915/skl: Implement WaDisableHBR2
  drm/i915: Remove the preliminary_hw_support shackles from CHV
  drm/i915: Read CHV_PLL_DW8 from the correct offset
  drm/i915: Rewrite IVB FDI bifurcation conflict checks
  drm/i915: Rewrite some some of the FDI lane checks
  drm/i915/skl: Enable the RPS interrupts programming
  drm/i915/skl: Enabling processing of Turbo interrupts
  drm/i915/skl: Updated the i915_frequency_info debugfs function
  drm/i915: Simplify the way BC bifurcation state consistency is kept
  drm/i915/skl: Updated the act_freq_mhz_show sysfs function
  drm/i915/skl: Updated the gen9_enable_rps function
  drm/i915/skl: Updated the gen6_rps_limits function
  drm/i915/skl: Restructured the gen6_set_rps_thresholds function
  drm/i915/skl: Updated the gen6_set_rps function
  drm/i915/skl: Updated the gen6_init_rps_frequencies function
  ...

1 files changed, 8 insertions, 3 deletions

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 0d15e6e30732..132581ca4ad8 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -733,10 +733,14 @@ static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
 			      struct drm_dp_sideband_msg_tx *txmsg)
 {
 	bool ret;
-	mutex_lock(&mgr->qlock);
+
+	/*
+	 * All updates to txmsg->state are protected by mgr->qlock, and the two
+	 * cases we check here are terminal states. For those the barriers
+	 * provided by the wake_up/wait_event pair are enough.
+	 */
 	ret = (txmsg->state == DRM_DP_SIDEBAND_TX_RX ||
 	       txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT);
-	mutex_unlock(&mgr->qlock);
 	return ret;
 }
 
@@ -1363,12 +1367,13 @@ static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
 	return 0;
 }
 
-/* must be called holding qlock */
 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
 {
 	struct drm_dp_sideband_msg_tx *txmsg;
 	int ret;
 
+	WARN_ON(!mutex_is_locked(&mgr->qlock));
+
 	/* construct a chunk from the first msg in the tx_msg queue */
 	if (list_empty(&mgr->tx_msg_downq)) {
 		mgr->tx_down_in_progress = false;