Re: [PATCH v2 07/11] drm/ttm: drop VM_DONTDUMP

From: Koenig, Christian
Date: Tue Sep 17 2019 - 07:22:40 EST


Am 17.09.19 um 11:24 schrieb Gerd Hoffmann:
> Not obvious why this is needed. According to Deniel Vetter this is most
> likely a historic artefact dating back to the days where drm drivers
> exposed hardware registers as mmap'able gem objects, to avoid dumping
> touching those registers.

Clearly a NAK.

We still have that and really don't want to try dumping any CPU
inaccessible VRAM content even if it is mapped into the address space
somewhere.

Regards,
Christian.

>
> Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>
> ---
> drivers/gpu/drm/ttm/ttm_bo_vm.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
> index 7c0e85c10e0e..4dc77a66aaf6 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
> @@ -445,7 +445,7 @@ void ttm_bo_mmap_vma_setup(struct ttm_buffer_object *bo, struct vm_area_struct *
> * VM_MIXEDMAP on all mappings. See freedesktop.org bug #75719
> */
> vma->vm_flags |= VM_MIXEDMAP;
> - vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
> + vma->vm_flags |= VM_IO | VM_DONTEXPAND;
> }
> EXPORT_SYMBOL(ttm_bo_mmap_vma_setup);
>