drm/tegra: Fix NULL deref in debugfs/iova
When IOMMU is off, ->mm_lock is not initialized and ->mm is NULL.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
index eddea77..86b3e1c 100644
--- a/drivers/gpu/drm/tegra/drm.c
+++ b/drivers/gpu/drm/tegra/drm.c
@@ -1033,9 +1033,11 @@ static int tegra_debugfs_iova(struct seq_file *s, void *data)
struct tegra_drm *tegra = drm->dev_private;
struct drm_printer p = drm_seq_file_printer(s);
- mutex_lock(&tegra->mm_lock);
- drm_mm_print(&tegra->mm, &p);
- mutex_unlock(&tegra->mm_lock);
+ if (tegra->domain) {
+ mutex_lock(&tegra->mm_lock);
+ drm_mm_print(&tegra->mm, &p);
+ mutex_unlock(&tegra->mm_lock);
+ }
return 0;
}