drm/exynos: drop struct_mutex from exynos_gem_map_sgt_with_dma

The sg table isn't refcounted, there's no corresponding locking for
unmapping and drm_map_sg is ok with being called concurrently.

So drop the locking since it doesn't protect anything.

Cc: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459330852-27668-8-git-send-email-daniel.vetter@ffwll.ch

diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c
index 3b7209335df0bd2e2a52db5c9d4da310cfe86e40..60b9975bb0b1c62f0dc5efcd2be7d112e82d76c0 100644 (file)
--- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
@@ -388,16 +388,12 @@ int exynos_gem_map_sgt_with_dma(struct drm_device *drm_dev,
 {
        int nents;
 
-       mutex_lock(&drm_dev->struct_mutex);
-
        nents = dma_map_sg(to_dma_dev(drm_dev), sgt->sgl, sgt->nents, dir);
        if (!nents) {
                DRM_ERROR("failed to map sgl with dma.\n");
-               mutex_unlock(&drm_dev->struct_mutex);
                return nents;
        }
 
-       mutex_unlock(&drm_dev->struct_mutex);
        return 0;
 }