drm/i915/overlay: Drop struct_mutex guard

The overlay uses the modeset mutex to control itself and only required
the struct_mutex for requests, which is now obsolete.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191004134015.13204-16-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/display/intel_display.c

@@ -5738,13 +5738,8 @@ void hsw_disable_ips(const struct intel_crtc_state *crtc_state)
 
 static void intel_crtc_dpms_overlay_disable(struct intel_crtc *intel_crtc)
 {
-	if (intel_crtc->overlay) {
-		struct drm_device *dev = intel_crtc->base.dev;
-
-		mutex_lock(&dev->struct_mutex);
+	if (intel_crtc->overlay)
 		(void) intel_overlay_switch_off(intel_crtc->overlay);
-		mutex_unlock(&dev->struct_mutex);
-	}
 
 	/* Let userspace switch the overlay on again. In most cases userspace
 	 * has to recompute where to put it anyway.

drivers/gpu/drm/i915/display/intel_overlay.c

@@ -439,8 +439,6 @@ static int intel_overlay_release_old_vid(struct intel_overlay *overlay)
 	struct i915_request *rq;
 	u32 *cs;
 
-	lockdep_assert_held(&dev_priv->drm.struct_mutex);
-
 	/*
 	 * Only wait if there is actually an old frame to release to
 	 * guarantee forward progress.
@@ -751,7 +749,6 @@ static int intel_overlay_do_put_image(struct intel_overlay *overlay,
 	struct i915_vma *vma;
 	int ret, tmp_width;
 
-	lockdep_assert_held(&dev_priv->drm.struct_mutex);
 	WARN_ON(!drm_modeset_is_locked(&dev_priv->drm.mode_config.connection_mutex));
 
 	ret = intel_overlay_release_old_vid(overlay);
@@ -852,7 +849,6 @@ int intel_overlay_switch_off(struct intel_overlay *overlay)
 	struct drm_i915_private *dev_priv = overlay->i915;
 	int ret;
 
-	lockdep_assert_held(&dev_priv->drm.struct_mutex);
 	WARN_ON(!drm_modeset_is_locked(&dev_priv->drm.mode_config.connection_mutex));
 
 	ret = intel_overlay_recover_from_interrupt(overlay);
@@ -1068,11 +1064,7 @@ int intel_overlay_put_image_ioctl(struct drm_device *dev, void *data,
 
 	if (!(params->flags & I915_OVERLAY_ENABLE)) {
 		drm_modeset_lock_all(dev);
-		mutex_lock(&dev->struct_mutex);
-
 		ret = intel_overlay_switch_off(overlay);
-
-		mutex_unlock(&dev->struct_mutex);
 		drm_modeset_unlock_all(dev);
 
 		return ret;
@@ -1088,7 +1080,6 @@ int intel_overlay_put_image_ioctl(struct drm_device *dev, void *data,
 		return -ENOENT;
 
 	drm_modeset_lock_all(dev);
-	mutex_lock(&dev->struct_mutex);
 
 	if (i915_gem_object_is_tiled(new_bo)) {
 		DRM_DEBUG_KMS("buffer used for overlay image can not be tiled\n");
@@ -1152,14 +1143,12 @@ int intel_overlay_put_image_ioctl(struct drm_device *dev, void *data,
 	if (ret != 0)
 		goto out_unlock;
 
-	mutex_unlock(&dev->struct_mutex);
 	drm_modeset_unlock_all(dev);
 	i915_gem_object_put(new_bo);
 
 	return 0;
 
 out_unlock:
-	mutex_unlock(&dev->struct_mutex);
 	drm_modeset_unlock_all(dev);
 	i915_gem_object_put(new_bo);
 
@@ -1233,7 +1222,6 @@ int intel_overlay_attrs_ioctl(struct drm_device *dev, void *data,
 	}
 
 	drm_modeset_lock_all(dev);
-	mutex_lock(&dev->struct_mutex);
 
 	ret = -EINVAL;
 	if (!(attrs->flags & I915_OVERLAY_UPDATE_ATTRS)) {
@@ -1290,7 +1278,6 @@ int intel_overlay_attrs_ioctl(struct drm_device *dev, void *data,
 
 	ret = 0;
 out_unlock:
-	mutex_unlock(&dev->struct_mutex);
 	drm_modeset_unlock_all(dev);
 
 	return ret;

drivers/gpu/drm/i915/gt/intel_reset.c

@@ -1288,10 +1288,6 @@ int intel_gt_terminally_wedged(struct intel_gt *gt)
 	if (!test_bit(I915_RESET_BACKOFF, &gt->reset.flags))
 		return -EIO;
 
-	/* XXX intel_reset_finish() still takes struct_mutex!!! */
-	if (mutex_is_locked(&gt->i915->drm.struct_mutex))
-		return -EAGAIN;
-
 	if (wait_event_interruptible(gt->reset.queue,
 				     !test_bit(I915_RESET_BACKOFF,
 					       &gt->reset.flags)))