Am 21.12.21 um 16:47 schrieb Thomas Hellström:
Hi, Christian,
On Tue, 2021-12-21 at 15:07 +0100, Christian König wrote:
First of all as discussed multiple times now kernel copies *must*
always wait
for all fences in a BO before actually doing the copy. This is
mandatory.
This patch looks ok to me.
Regarding the discussion I was just awaiting Daniel's reply from
yesterday:
https://lists.freedesktop.org/archives/intel-gfx/2021-December/285717.html
since his earlier reply
https://lists.freedesktop.org/archives/intel-gfx/2021-December/285717.html
contradicted your previous reply
https://lists.freedesktop.org/archives/intel-gfx/2021-December/284467.html
That confirmed all writes had to add an exclusive fence, and confirmed
that starting the blit early was ok.
So I was left a bit confused as to what the rules really were.
So now if I understand both of you correctly, writers that want to opt
out of implicit syncing do *not* need to add an exclusive fence. Is
that correct?
Yes, that's a good summary of the problem.
Additional to that drop the handling when there can't be a shared
slot
allocated on the source BO and just properly return an error code.
Otherwise
this code path would only be tested under out of memory conditions.
Good point.
Signed-off-by: Christian König <christian.koenig@xxxxxxx>
Reviewed-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
Ok if I add this to drm-intel-gt-next?
Please go ahead.
Thanks,
Christian.
/Thomas
