Merge tag 'drm-intel-next-2015-10-10' of git://anongit.freedesktop.org/drm-intel into drm-next

- dmc fixes from Animesh (not yet all) for deeper sleep states
- piles of prep patches from Ville to make mmio functions type-safe
- more fbc work from Paulo all over
- w/a shuffling from Arun Siluvery
- first part of atomic watermark updates from Matt and Ville (later parts had to
  be dropped again unfortunately)
- lots of patches to prepare bxt dsi support ( Shashank Sharma)
- userptr fixes from Chris
- audio rate interface between i915/snd_hda plus kerneldoc (Libin Yang)
- shrinker improvements and fixes (Chris Wilson)
- lots and lots of small patches all over

* tag 'drm-intel-next-2015-10-10' of git://anongit.freedesktop.org/drm-intel: (134 commits)
  drm/i915: Update DRIVER_DATE to 20151010
  drm/i915: Partial revert of atomic watermark series
  drm/i915: Early exit from semaphore_waits_for for execlist mode.
  drm/i915: Remove wrong warning from i915_gem_context_clean
  drm/i915: Determine the stolen memory base address on gen2
  drm/i915: fix FBC buffer size checks
  drm/i915: fix CFB size calculation
  drm/i915: remove pre-atomic check from SKL update_primary_plane
  drm/i915: don't allocate fbcon from stolen memory if it's too big
  Revert "drm/i915: Call encoder hotplug for init and resume cases"
  Revert "drm/i915: Add hot_plug hook for hdmi encoder"
  drm/i915: use error path
  drm/i915/irq: Fix misspelled word register in kernel-doc
  drm/i915/irq: Fix kernel-doc warnings
  drm/i915: Hook up ring workaround writes at context creation time on Gen6-7.
  drm/i915: Don't warn if the workaround list is empty.
  drm/i915: Resurrect golden context on gen6/7
  drm/i915/chv: remove pre-production hardware workarounds
  drm/i915/snb: remove pre-production hardware workaround
  drm/i915/bxt: Set time interval unit to 0.833us
  ...

drivers/gpu/drm/i915/i915_irq.c

@@ -581,6 +581,7 @@ i915_disable_pipestat(struct drm_i915_private *dev_priv, enum pipe pipe,
 
 /**
  * i915_enable_asle_pipestat - enable ASLE pipestat for OpRegion
+ * @dev: drm device
  */
 static void i915_enable_asle_pipestat(struct drm_device *dev)
 {
@@ -997,12 +998,16 @@ static bool vlv_c0_above(struct drm_i915_private *dev_priv,
 			 int threshold)
 {
 	u64 time, c0;
+	unsigned int mul = 100;
 
 	if (old->cz_clock == 0)
 		return false;
 
+	if (I915_READ(VLV_COUNTER_CONTROL) & VLV_COUNT_RANGE_HIGH)
+		mul <<= 8;
+
 	time = now->cz_clock - old->cz_clock;
-	time *= threshold * dev_priv->mem_freq;
+	time *= threshold * dev_priv->czclk_freq;
 
 	/* Workload can be split between render + media, e.g. SwapBuffers
 	 * being blitted in X after being rendered in mesa. To account for
@@ -1010,7 +1015,7 @@ static bool vlv_c0_above(struct drm_i915_private *dev_priv,
 	 */
 	c0 = now->render_c0 - old->render_c0;
 	c0 += now->media_c0 - old->media_c0;
-	c0 *= 100 * VLV_CZ_CLOCK_TO_MILLI_SEC * 4 / 1000;
+	c0 *= mul * VLV_CZ_CLOCK_TO_MILLI_SEC;
 
 	return c0 >= time;
 }
@@ -2388,6 +2393,7 @@ static void i915_error_wake_up(struct drm_i915_private *dev_priv,
 
 /**
  * i915_reset_and_wakeup - do process context error handling work
+ * @dev: drm device
  *
  * Fire an error uevent so userspace can see that a hang or error
  * was detected.
@@ -2565,7 +2571,7 @@ static void i915_report_and_clear_eir(struct drm_device *dev)
  * i915_handle_error - handle a gpu error
  * @dev: drm device
  *
- * Do some basic checking of regsiter state at error time and
+ * Do some basic checking of register state at error time and
  * dump it to the syslog.  Also call i915_capture_error_state() to make
  * sure we get a record and make it available in debugfs.  Fire a uevent
  * so userspace knows something bad happened (should trigger collection
@@ -2778,6 +2784,26 @@ semaphore_waits_for(struct intel_engine_cs *ring, u32 *seqno)
 	u64 offset = 0;
 	int i, backwards;
 
+	/*
+	 * This function does not support execlist mode - any attempt to
+	 * proceed further into this function will result in a kernel panic
+	 * when dereferencing ring->buffer, which is not set up in execlist
+	 * mode.
+	 *
+	 * The correct way of doing it would be to derive the currently
+	 * executing ring buffer from the current context, which is derived
+	 * from the currently running request. Unfortunately, to get the
+	 * current request we would have to grab the struct_mutex before doing
+	 * anything else, which would be ill-advised since some other thread
+	 * might have grabbed it already and managed to hang itself, causing
+	 * the hang checker to deadlock.
+	 *
+	 * Therefore, this function does not support execlist mode in its
+	 * current form. Just return NULL and move on.
+	 */
+	if (ring->buffer == NULL)
+		return NULL;
+
 	ipehr = I915_READ(RING_IPEHR(ring->mmio_base));
 	if (!ipehr_is_semaphore_wait(ring->dev, ipehr))
 		return NULL;