From: Alexandre Courbot <acourbot@nvidia.com>
Date: Thu, 3 Sep 2015 08:39:52 +0000 (+0900)
Subject: drm/nouveau/pmu: do not assume a PMU is present
X-Git-Tag: firefly_0821_release~176^2~493^2^2~56
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=579b7c58215329803ce184704463de09f0f310ac;p=firefly-linux-kernel-4.4.55.git

drm/nouveau/pmu: do not assume a PMU is present

Some devices may not have a PMU. Avoid a NULL pointer dereference in
such cases by checking whether the pointer given to nvkm_pmu_pgob() is
valid.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
---

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/pmu/base.c b/drivers/gpu/drm/nouveau/nvkm/subdev/pmu/base.c
index 27a79c0c3888..d95eb8659d1b 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/pmu/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/pmu/base.c
@@ -28,7 +28,7 @@
 void
 nvkm_pmu_pgob(struct nvkm_pmu *pmu, bool enable)
 {
-	if (pmu->func->pgob)
+	if (pmu && pmu->func->pgob)
 		pmu->func->pgob(pmu, enable);
 }