> > What is handle? What is point? > > Handle is a syncobj handle, point is the point in a syncobj timeline. > I'll document those fields. OK. > > Why is there padding instead of putting point first? > > We can move the point field first, but we need to keep the explicit > padding: the struct has to be 64bit aligned because of the __u64 field > (which the compiler takes care of) but if we don't have an explicit > padding, the unused 32bits are undefined, which might cause trouble if > we extend the struct at some point, since we sort of expect that old > userspace keep this unused 32bit slot to 0, while new users set > non-zero values if they have to. Makes sense. Reordering still probably makes sense. > > ``` > > > #define PANFROST_BO_REF_EXCLUSIVE 0x1 > > > +#define PANFROST_BO_REF_NO_IMPLICIT_DEP 0x2 > > ``` > > > > This seems logically backwards. NO_IMPLICIT_DEP makes sense if we're > > trying to keep backwards compatibility, but here you're crafting a new > > interface totally from scratch. If anything, isn't BO_REF_IMPLICIT_DEP > > the flag you'd want? > > AFAICT, all other drivers make the no-implicit-dep an opt-in, and I > didn't want to do things differently in panfrost. But if that's really > an issue, I can make it an opt-out. I don't have strong feelings either way. I was just under the impressions other drivers did this for b/w compat reasons which don't apply here. > > Hmm. I'm not /opposed/ and I know kbase uses strides but it seems like > > somewhat unwarranted complexity, and there is a combinatoric explosion > > here (if jobs, bo refs, and syncobj refs use 3 different versions, as > > this encoding permits... as opposed to just specifying a UABI version or > > something like that) > > Sounds like a good idea. I'll add a version field and map that > to a <job_stride,bo_ref_stride,syncobj_ref_stride> tuple. Cc Steven, does this make sense? > > > + /** > > > + * If the submission fails, this encodes the index of the job > > > + * failed. > > > + */ > > > + __u32 fail_idx; > > ``` > > > > What if multiple jobs fail? > > We stop at the first failure. Note that it's not an execution failure, > but a submission failure (AKA, userspace passed wrong params, like > invalid BO or synobj handles). I see, ok.
