[PATCH 10/10] drm/exynos: consider memory releasing to exported gem buffer into dmabuf

[Rob Clark]

On Wed, Jun 27, 2012 at 3:03 AM, Inki Dae <inki.dae at samsung.com> wrote:
> exported gem buffer into dmabuf should be released when a gem relese is
> requested by user. with dma_buf_put() call, if file->f_count is 0 then
> a release callback of exynos gem module(exporter) will be called to release
> its own gem buffer.
>
> Signed-off-by: Inki Dae <inki.dae at samsung.com>
> Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
> ---
>  drivers/gpu/drm/exynos/exynos_drm_drv.c |    1 +
>  drivers/gpu/drm/exynos/exynos_drm_gem.c |   16 ++++++++++++++++
>  drivers/gpu/drm/exynos/exynos_drm_gem.h |    4 ++++
>  3 files changed, 21 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c b/drivers/gpu/drm/exynos/exynos_drm_drv.c
> index d6de2e0..1501dd2 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_drv.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c
> @@ -258,6 +258,7 @@ static struct drm_driver exynos_drm_driver = {
>        .gem_init_object        = exynos_drm_gem_init_object,
>        .gem_free_object        = exynos_drm_gem_free_object,
>        .gem_vm_ops             = &exynos_drm_gem_vm_ops,
> +       .gem_close_object       = exynos_drm_gem_close_object,
>        .dumb_create            = exynos_drm_gem_dumb_create,
>        .dumb_map_offset        = exynos_drm_gem_dumb_map_offset,
>        .dumb_destroy           = exynos_drm_gem_dumb_destroy,
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c
> index 411d82b..5ca8641 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
> @@ -27,6 +27,7 @@
>  #include "drm.h"
>
>  #include <linux/shmem_fs.h>
> +#include <linux/dma-buf.h>
>  #include <drm/exynos_drm.h>
>
>  #include "exynos_drm_drv.h"
> @@ -749,6 +750,21 @@ int exynos_drm_gem_dumb_destroy(struct drm_file *file_priv,
>        return 0;
>  }
>
> +void exynos_drm_gem_close_object(struct drm_gem_object *obj,
> +                               struct drm_file *file)
> +{
> +       DRM_DEBUG_KMS("%s\n", __FILE__);
> +
> +       /*
> +        * exported dmabuf should be released when a gem is released by user.
> +        * with dma_buf_put() call, if file->f_count is 0 then a release
> +        * callback of gem module(exporter) will be called to release
> +        * its own gem buffer.
> +        */
> +       if (obj->export_dma_buf)
> +               dma_buf_put(obj->export_dma_buf);

this doesn't seem quite right to me..  although I think the dmabuf
release fxn needs to NULL out the obj->export_dma_buf.

If your GEM obj is getting released before your dmabuf then there is
something going wrong with the ref cnt'ing.

BR,
-R

> +}
> +
>  int exynos_drm_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
>  {
>        struct drm_gem_object *obj = vma->vm_private_data;
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.h b/drivers/gpu/drm/exynos/exynos_drm_gem.h
> index 14d038b..4f1ba1a 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_gem.h
> +++ b/drivers/gpu/drm/exynos/exynos_drm_gem.h
> @@ -162,4 +162,8 @@ int exynos_drm_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf);
>  /* set vm_flags and we can change the vm attribute to other one at here. */
>  int exynos_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma);
>
> +/* do extra release exynos gem module needs when gem close is called. */
> +void exynos_drm_gem_close_object(struct drm_gem_object *obj,
> +                               struct drm_file *file);
> +
>  #endif
> --
> 1.7.4.1
>
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