From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Date: Tue, 12 Sep 2017 15:37:47 +0200
Subject: drm/legacy: Convert setplane ioctl locking to interruptible.
Git-commit: 13736ba3b38b1b50979eaafd2e63ab9da146a059
Patch-mainline: v4.15-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Pass DRM_MODESET_ACQUIRE_INTERRUPTIBLE to acquire_init, and handle
drm_modeset_backoff which can now fail by returning the error.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20170912133749.6532-5-maarten.lankhorst@linux.intel.com
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/drm_plane.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

--- a/drivers/gpu/drm/drm_plane.c
+++ b/drivers/gpu/drm/drm_plane.c
@@ -667,7 +667,7 @@ static int setplane_internal(struct drm_
 	struct drm_modeset_acquire_ctx ctx;
 	int ret;
 
-	drm_modeset_acquire_init(&ctx, 0);
+	drm_modeset_acquire_init(&ctx, DRM_MODESET_ACQUIRE_INTERRUPTIBLE);
 retry:
 	ret = drm_modeset_lock_all_ctx(plane->dev, &ctx);
 	if (ret)
@@ -678,8 +678,9 @@ retry:
 
 fail:
 	if (ret == -EDEADLK) {
-		drm_modeset_backoff(&ctx);
-		goto retry;
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry;
 	}
 	drm_modeset_drop_locks(&ctx);
 	drm_modeset_acquire_fini(&ctx);