Re: [PATCH 1/2] drm/exynos: fix DMA_ATTR_NO_KERNEL_MAPPING usage

[Joonyoung Shim <jy0922.shim@samsung.com>]

Hi,

On 02/03/2015 05:47 PM, Carlo Caione wrote:
> The Exynos DRM driver doesn't follow the correct API when dealing with
> dma_{alloc, mmap, free}_attrs functions and the
> DMA_ATTR_NO_KERNEL_MAPPING attribute.
> 
> When a IOMMU is not available and the DMA_ATTR_NO_KERNEL_MAPPING is
> used, the driver should use the pointer returned by dma_alloc_attr() as
> a cookie.
> 
> The Exynos DRM driver directly uses the non-requested virtual
> kernel address returned by the DMA mapping subsystem. This just works
> now because the non-IOMMU codepath doesn't obey
> DMA_ATTR_NO_KERNEL_MAPPING but we need to fix it before fixing the DMA
> layer.
> 
> Signed-off-by: Carlo Caione <carlo@caione.org>
> ---
>  drivers/gpu/drm/exynos/exynos_drm_buf.c   |  6 +++---
>  drivers/gpu/drm/exynos/exynos_drm_fbdev.c | 29 +++++++++--------------------
>  drivers/gpu/drm/exynos/exynos_drm_gem.h   |  2 ++
>  3 files changed, 14 insertions(+), 23 deletions(-)
> 

Acked-by: Joonyoung Shim <jy0922.shim@samsung.com>

Thanks.