Am 26.05.21 um 15:12 schrieb Daniel Stone:
Hi,
On Wed, 26 May 2021 at 13:46, Christian König <christian.koenig@xxxxxxx> wrote:
Am 26.05.21 um 13:31 schrieb Daniel Stone:
How would we insert a syncobj+val into a resv though? Like, if we pass
an unmaterialised syncobj+val here to insert into the resv, then an
implicit-only media user (or KMS) goes to sync against the resv, what
happens?
Well this is for exporting, not importing. So we don't need to worry
about that.
It's just my thinking because the drm_syncobj is the backing object on
VkSemaphore implementations these days, isn't it?
Yeah, I can see that to an extent. But then binary vs. timeline
syncobjs are very different in use (which is unfortunate tbh), and
then we have an asymmetry between syncobj export & sync_file import.
You're right that we do want a syncobj though. This is probably not
practical due to smashing uAPI to bits, but if we could wind the clock
back a couple of years, I suspect the interface we want is that export
can either export a sync_file or a binary syncobj, and further that
binary syncobjs could transparently act as timeline semaphores by
mapping any value (either wait or signal) to the binary signal. In
hindsight, we should probably just never have had binary syncobj. Oh
well.
Well the later is the case IIRC. Don't ask me for the detail semantics,
but in general the drm_syncobj in timeline mode is compatible to the
binary mode.
The sync_file is also import/exportable to a certain drm_syncobj
timeline point (or as binary signal). So no big deal, we are all
compatible here :)
I just thought that it might be more appropriate to return a drm_syncobj
directly instead of a sync_file.
Regards,
Christian.
Cheers,
Daniel
