drm/i915/guc: Release GuC interrupts in i915_guc_submission_disable

Like capture of GuC interrupts while enabling GuC submission, release
them while disabling GuC submission.

Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1489199821-6707-1-git-send-email-sagar.a.kamble@intel.com
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c
index 41f2dd8..01b611c 100644
--- a/drivers/gpu/drm/i915/i915_guc_submission.c
+++ b/drivers/gpu/drm/i915/i915_guc_submission.c
@@ -995,10 +995,33 @@ int i915_guc_submission_enable(struct drm_i915_private *dev_priv)
 	return 0;
 }
 
+static void guc_interrupts_release(struct drm_i915_private *dev_priv)
+{
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+	int irqs;
+
+	/*
+	 * tell all command streamers NOT to forward interrupts or vblank
+	 * to GuC.
+	 */
+	irqs = _MASKED_FIELD(GFX_FORWARD_VBLANK_MASK, GFX_FORWARD_VBLANK_NEVER);
+	irqs |= _MASKED_BIT_DISABLE(GFX_INTERRUPT_STEERING);
+	for_each_engine(engine, dev_priv, id)
+		I915_WRITE(RING_MODE_GEN7(engine), irqs);
+
+	/* route all GT interrupts to the host */
+	I915_WRITE(GUC_BCS_RCS_IER, 0);
+	I915_WRITE(GUC_VCS2_VCS1_IER, 0);
+	I915_WRITE(GUC_WD_VECS_IER, 0);
+}
+
 void i915_guc_submission_disable(struct drm_i915_private *dev_priv)
 {
 	struct intel_guc *guc = &dev_priv->guc;
 
+	guc_interrupts_release(dev_priv);
+
 	if (!guc->execbuf_client)
 		return;