From: Ben Skeggs <bskeggs@redhat.com>
Date: Mon, 12 Dec 2016 23:29:55 +0000 (+1000)
Subject: drm/nouveau/ltc: protect clearing of comptags with mutex
X-Git-Tag: v4.8.17~71
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=82d9824d94467b20469dde7291c68012a36e80bf;p=thirdparty%2Fkernel%2Fstable.git

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

commit f4e65efc88b64c1dbca275d42a188edccedb56c6 upstream.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/ltc/base.c b/drivers/gpu/drm/nouveau/nvkm/subdev/ltc/base.c
index 39c2a38e54f74..0c7ef250dcafc 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