| Message ID | 20190917092404.9982-8-kraxel@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm: rework mmap() workflow | expand |
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@redhat.com> > --- > 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); >
On Tue, Sep 17, 2019 at 11:22:35AM +0000, Koenig, Christian wrote: > 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. Thanks for the clarification, I'll drop the patch. cheers, Gerd
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);
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. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> --- drivers/gpu/drm/ttm/ttm_bo_vm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)