Re: [PATCH 1/2] drm/shmem-helpers: revert "Redirect mmap for imported dma-buf"

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Am 15.09.20 um 12:39 schrieb Daniel Vetter:
On Mon, Sep 14, 2020 at 3:29 PM Christian König
<ckoenig.leichtzumerken@xxxxxxxxx> wrote:
This reverts commit 26d3ac3cb04d171a861952e89324e347598a347f.

We need to figure out if dma_buf_mmap() is valid or not first.

Signed-off-by: Christian König <christian.koenig@xxxxxxx>
The trouble is that doing dma-buf mmap by looking at the struct pages
behind the sg list and just inserting those into userspace doesn't
really work any better. You still won't get the unmap_mapping_range
and hence pte shoot-down. So maybe dma_buf_mmap forwarding doesn't
work, but this doesn't make it any better.

Good point. Question is what should we do? Return -EPERM?


Also commit message should probably explain a bit the context here,
not a lot of people have been in our private discussion on this.

Well, that's certain true.

Christian.

-Daniel

---
  drivers/gpu/drm/drm_gem_shmem_helper.c | 3 ---
  1 file changed, 3 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 0a952f27c184..cd727343f72b 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -594,9 +594,6 @@ int drm_gem_shmem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
         /* Remove the fake offset */
         vma->vm_pgoff -= drm_vma_node_start(&obj->vma_node);

-       if (obj->import_attach)
-               return dma_buf_mmap(obj->dma_buf, vma, 0);
-
         shmem = to_drm_gem_shmem_obj(obj);

         ret = drm_gem_shmem_get_pages(shmem);
--
2.17.1

_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/dri-devel






[Index of Archives]     [Linux Input]     [Video for Linux]     [Gstreamer Embedded]     [Mplayer Users]     [Linux USB Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [Yosemite Backpacking]

  Powered by Linux