[PATCH v3.18-rc3] drm: msm: Allow exported dma-bufs to be mapped

[Rob Clark]

On Mon, Nov 10, 2014 at 12:16 PM, Daniel Thompson
<daniel.thompson at linaro.org> wrote:
> diff --git a/drivers/gpu/drm/msm/msm_gem_prime.c b/drivers/gpu/drm/msm/msm_gem_prime.c
> index ad772fe36115..4e4fa5828d5d 100644
> --- a/drivers/gpu/drm/msm/msm_gem_prime.c
> +++ b/drivers/gpu/drm/msm/msm_gem_prime.c
> @@ -20,6 +20,14 @@
>
>  #include <linux/dma-buf.h>
>
> +struct dma_buf *msm_gem_prime_export(struct drm_device *dev,
> +                                    struct drm_gem_object *obj, int flags)
> +{
> +       /* we want to be able to write in mmapped buffer */
> +       flags |= O_RDWR;
> +       return drm_gem_prime_export(dev, obj, flags);
> +}
> +

seems like this probably should be done more centrally..  and in fact,
might be better to have something like this in
drm_prime_handle_to_fd_ioctl:

    /* check flags are valid */
-    if (args->flags & ~DRM_CLOEXEC)
+    if (args->flags & ~(DRM_CLOEXEC | O_RDWR))
       return -EINVAL;

so exporter can specify whether to allow mmap or not..

BR,
-R