Questions about TTM buffer object maping
Jerome Glisse
j.glisse at gmail.com
Thu Jul 11 14:51:08 PDT 2013
On Thu, Jul 11, 2013 at 5:43 PM, Jean-Sébastien Pédron
<jean-sebastien.pedron at dumbbell.fr> wrote:
> Hi,
>
> Thank you Jérôme and Daniel for your input, that's really helpful!
>
> I have another question: in ttm_bo_mmap(), a reference to the buffer object
> is acquired at the beginning of the function. Another reference is acquired
> in ttm_bo_vm_open() (released in ttm_bo_vm_close()).
>
> But where is the first reference released?
>
> --
> Jean-Sébastien Pédron
the ttm_bo_vm_open is not call on first time a vma is mmap, ie when
userspace do mmap it call driver
mmap callback which call ttm_bo_mmap but ttm_bo_vm_open is never call.
If the same process or
another process mmap the same area or subarea the ttm_bo_vm_open is
call. Then on each unmap
ttm_bo_vm_close is call.
Cheers,
Jerome
More information about the dri-devel
mailing list