On 28/10/2021 16:30, Daniel Vetter wrote:
On Thu, Oct 28, 2021 at 10:41:38AM +0200, Christian König wrote:
Am 21.10.21 um 13:13 schrieb Tvrtko Ursulin:
On 21/10/2021 12:06, Maarten Lankhorst wrote:
Op 21-10-2021 om 12:38 schreef Christian König:
Am 21.10.21 um 12:35 schrieb Maarten Lankhorst:
From: Christian König <christian.koenig@xxxxxxx>
Simplifying the code a bit.
Signed-off-by: Christian König <christian.koenig@xxxxxxx>
[mlankhorst: Handle timeout = 0 correctly, use new
i915_request_wait_timeout.]
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
LGTM, do you want to push it or should I pick it up into drm-misc-next?
I think it can be applied to drm-intel-gt-next, after a backmerge.
It needs patch 1 too, which fixes
i915_request_wait semantics when used in dma-fence. It exports a
dma-fence compatible i915_request_wait_timeout function, used in
this patch.
What about the other i915 patches? I guess you then want to merge them
through drm-intel-gt-next as well.
I don't think my open has been resolved, at least I haven't seen a reply
from Daniel on the topic of potential for infinite waits with untrusted
clients after this change. +Daniel
Please resolve that internally and let me know the result. I'm fine to use
any of the possible approaches, I just need to know which one.
I thought I explained this in the patch set from Maarten. This isn't an
issue, since the exact same thing can happen if you get interrupts and
stuff.
Ah were you trying to point out all this time the infinite wait just got
moved from inside the "old" dma_resv_get_fences to the new iterator caller?
Regards,
Tvrtko
The only proper fix for bounding the waits is a) compositor grabs a stable
set of dma_fence from the dma-buf through the proposed fence export ioctl
b) compositor waits on that fence (or drm_syncobj).
Everything else is cargo-culted nonsense, and very much includes that igt
patch that's floating around internally.
I can also whack this into drm-next if this is stuck in this silly
bikeshed.
-Daniel
