4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> commit 120a264f9c2782682027d931d83dcbd22e01da80 upstream. When no IOMMU is available, all GEM buffers allocated by Exynos DRM driver are contiguous, because of the underlying dma_alloc_attrs() function provides only such buffers. In such case it makes no sense to keep BO_NONCONTIG flag for the allocated GEM buffers. This allows to avoid failures for buffer contiguity checks in the subsequent operations on GEM objects. Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> Signed-off-by: Inki Dae <inki.dae@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/exynos/exynos_drm_gem.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/drivers/gpu/drm/exynos/exynos_drm_gem.c +++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c @@ -245,6 +245,15 @@ struct exynos_drm_gem *exynos_drm_gem_cr if (IS_ERR(exynos_gem)) return exynos_gem; + if (!is_drm_iommu_supported(dev) && (flags & EXYNOS_BO_NONCONTIG)) { + /* + * when no IOMMU is available, all allocated buffers are + * contiguous anyway, so drop EXYNOS_BO_NONCONTIG flag + */ + flags &= ~EXYNOS_BO_NONCONTIG; + DRM_WARN("Non-contiguous allocation is not supported without IOMMU, falling back to contiguous buffer\n"); + } + /* set memory type and cache attribute from user side. */ exynos_gem->flags = flags;