[PATCH 2/5] drm/exynos: iommu: add a check if all sub-devices have iommu controller

[Marek Szyprowski]

This patch adds a check if all devices belonging to Exynos DRM have the
same dma_map_ops set. This is required to enable operation with IOMMU
enabled.

Signed-off-by: Marek Szyprowski <m.szyprowski at samsung.com>
---
 drivers/gpu/drm/exynos/exynos_drm_iommu.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_iommu.c 
b/drivers/gpu/drm/exynos/exynos_drm_iommu.c
index 1e82529..36dde96 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_iommu.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_iommu.c
@@ -97,6 +97,11 @@ int drm_iommu_attach_device(struct drm_device *drm_dev,
        if (!priv->mapping)
                return 0;

+       if (get_dma_ops(priv->dma_dev) != get_dma_ops(subdrv_dev)) {
+               DRM_ERROR("Device %s lacks support for IOMMU\n",
+                         dev_name(subdrv_dev));
+               return -EINVAL;
+       }

        ret = configure_dma_max_seg_size(subdrv_dev);
        if (ret)
-- 
1.9.2