This is a note to let you know that I've just added the patch titled drm/exynos: gem: Drop NONCONTIG flag for buffers allocated without IOMMU to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-exynos-gem-drop-noncontig-flag-for-buffers-allocated-without-iommu.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 120a264f9c2782682027d931d83dcbd22e01da80 Mon Sep 17 00:00:00 2001 From: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> Date: Wed, 22 Nov 2017 14:14:47 +0100 Subject: drm/exynos: gem: Drop NONCONTIG flag for buffers allocated without IOMMU 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 @@ -246,6 +246,15 @@ 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; Patches currently in stable-queue which might be from m.szyprowski@xxxxxxxxxxx are queue-4.9/drm-exynos-gem-drop-noncontig-flag-for-buffers-allocated-without-iommu.patch