[Intel-gfx] [PATCH] drm/i915: Fix set_caching locking

[Ben Widawsky]

On the EINVAL case we don't release struct_mutex. It should be safe to
grab the lock after checking the parameters, which also resolves the
issues.

Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
---
 drivers/gpu/drm/i915/i915_gem.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 365a7dc..76bbb37 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3218,10 +3218,6 @@ int i915_gem_set_caching_ioctl(struct drm_device *dev, void *data,
 	enum i915_cache_level level;
 	int ret;
 
-	ret = i915_mutex_lock_interruptible(dev);
-	if (ret)
-		return ret;
-
 	switch (args->caching) {
 	case I915_CACHING_NONE:
 		level = I915_CACHE_NONE;
@@ -3233,6 +3229,10 @@ int i915_gem_set_caching_ioctl(struct drm_device *dev, void *data,
 		return -EINVAL;
 	}
 
+	ret = i915_mutex_lock_interruptible(dev);
+	if (ret)
+		return ret;
+
 	obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
 	if (&obj->base == NULL) {
 		ret = -ENOENT;
-- 
1.7.12.1