commit f4e65efc88b64c1dbca275d42a188edccedb56c6
author Ben Skeggs <bskeggs@redhat.com> Tue Dec 13 09:29:55 2016 +1000
committer Ben Skeggs <bskeggs@redhat.com> Tue Dec 13 11:40:09 2016 +1000
tree 358ba57ac8f56d8075e1c7feca22121dac7e594c
parent 64373e4bb6e13f571145d32202907cdffe861550

drm/nouveau/ltc: protect clearing of comptags with mutex

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Cc: stable@vger.kernel.org

drivers/gpu/drm/nouveau/nvkm/subdev/ltc/base.c

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/ltc/base.c b/drivers/gpu/drm/nouveau/nvkm/subdev/ltc/base.c
index 39c2a38..0c7ef25 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/ltc/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/ltc/base.c
@@ -47,8 +47,10 @@ nvkm_ltc_tags_clear(struct nvkm_ltc *ltc, u32 first, u32 count)
 
 	BUG_ON((first > limit) || (limit >= ltc->num_tags));
 
+	mutex_lock(&ltc->subdev.mutex);
 	ltc->func->cbc_clear(ltc, first, limit);
 	ltc->func->cbc_wait(ltc);
+	mutex_unlock(&ltc->subdev.mutex);
 }
 
 int