On 2022-02-24 05:29, Lu Baolu wrote:
On 2/24/22 1:16 PM, Lu Baolu wrote:
Hi Robin and Jason,
On 2/24/22 2:02 AM, Jason Gunthorpe wrote:
On Wed, Feb 23, 2022 at 06:00:06PM +0000, Robin Murphy wrote:
...and equivalently just set owner_cnt directly to 0 here. I don't
see a
realistic use-case for any driver to claim the same group more than
once,
and allowing it in the API just feels like opening up various potential
corners for things to get out of sync.
I am Ok if we toss it out to get this merged, as there is no in-kernel
user right now.
So we don't need the owner pointer in the API anymore, right?
Oh, NO.
The owner token represents that the group has been claimed for user
space access. And the default domain auto-attach policy will be changed
accordingly.
So we still need this. Sorry for the noise.
Exactly. In fact we could almost go the other way, and rename owner_cnt
to dma_api_users and make it mutually exclusive with owner being set,
but that's really just cosmetic. It's understandable enough as-is that
owner_cnt > 0 with owner == NULL represents implicit DMA API ownership.
Cheers,
Robin.
