drm/i915: Extend rpm wakelock during i915_handle_error()

We take the runtime pm wakelock during i915_handle_error() to ensure
that all paths that reach the error handler keep the device awake during
the hw reads. However, we need to extend that from the reset handler to
include the earlier capture routines.
Reported-by: NAntonio Argenziano <antonio.argenziano@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Michel Thierry <michel.thierry@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170314171840.25706-1-chris@chris-wilson.co.ukReviewed-by: NMichel Thierry <michel.thierry@intel.com>

drivers/gpu/drm/i915/i915_irq.c

@@ -2664,14 +2664,6 @@ static void i915_reset_and_wakeup(struct drm_i915_private *dev_priv)
 	DRM_DEBUG_DRIVER("resetting chip\n");
 	kobject_uevent_env(kobj, KOBJ_CHANGE, reset_event);
 
-	/*
-	 * In most cases it's guaranteed that we get here with an RPM
-	 * reference held, for example because there is a pending GPU
-	 * request that won't finish until the reset is done. This
-	 * isn't the case at least when we get here by doing a
-	 * simulated reset via debugs, so get an RPM reference.
-	 */
-	intel_runtime_pm_get(dev_priv);
 	intel_prepare_reset(dev_priv);
 
 	do {
@@ -2693,7 +2685,6 @@ static void i915_reset_and_wakeup(struct drm_i915_private *dev_priv)
 				     HZ));
 
 	intel_finish_reset(dev_priv);
-	intel_runtime_pm_put(dev_priv);
 
 	if (!test_bit(I915_WEDGED, &dev_priv->gpu_error.flags))
 		kobject_uevent_env(kobj,
@@ -2780,15 +2771,24 @@ void i915_handle_error(struct drm_i915_private *dev_priv,
 	vscnprintf(error_msg, sizeof(error_msg), fmt, args);
 	va_end(args);
 
+	/*
+	 * In most cases it's guaranteed that we get here with an RPM
+	 * reference held, for example because there is a pending GPU
+	 * request that won't finish until the reset is done. This
+	 * isn't the case at least when we get here by doing a
+	 * simulated reset via debugfs, so get an RPM reference.
+	 */
+	intel_runtime_pm_get(dev_priv);
+
 	i915_capture_error_state(dev_priv, engine_mask, error_msg);
 	i915_clear_error_registers(dev_priv);
 
 	if (!engine_mask)
-		return;
+		goto out;
 
 	if (test_and_set_bit(I915_RESET_IN_PROGRESS,
 			     &dev_priv->gpu_error.flags))
-		return;
+		goto out;
 
 	/*
 	 * Wakeup waiting processes so that the reset function
@@ -2805,6 +2805,9 @@ void i915_handle_error(struct drm_i915_private *dev_priv,
 	i915_error_wake_up(dev_priv);
 
 	i915_reset_and_wakeup(dev_priv);
+
+out:
+	intel_runtime_pm_put(dev_priv);
 }
 
 /* Called from drm generic code, passed 'crtc' which