On Wed, Jun 26, 2024 at 08:26:04PM +0100, Daniel Stone wrote: > On Wed, 26 Jun 2024 at 18:52, Daniel Vetter <daniel@xxxxxxxx> wrote: > > On Wed, Jun 26, 2024 at 11:39:01AM +0100, Daniel Stone wrote: > > > On Wed, 26 Jun 2024 at 09:28, Lucas Stach <l.stach@xxxxxxxxxxxxxx> wrote: > > > > So we are kind of stuck here between breaking one or the other use- > > > > case. I'm leaning heavily into the direction of just fixing Mesa, so we > > > > can specify the type of screen we need at creation time to avoid the > > > > renderonly issue, porting this change as far back as reasonably > > > > possible and file old userspace into shit-happens. > > > > > > Yeah, honestly this sounds like the best solution to me too. > > > > Yeah mesa sounds kinda broken here ... > > > > What might work in the kernel is if you publish a fake 3d engine that's > > too new for broken mesa, if that's enough to make it fail to bind? And if > > mesa still happily binds against that, then yeah it's probably too broken > > and we need etnaviv-v2 (as a drm driver uapi name, I think that's what > > mesa filters?) for anything new (including the NN-only ones). > > > > I would still try to avoid that, but just in case someone screams about > > regressions. > > It's not just etnaviv, it's literally every Mesa driver which works > with decoupled render/display. So that would be etnaviv-v2, > panfrost-v2, panthor-v2, v3d-v2, powervr-v2, ... albeit those don't > tend to have multiple instances. So essentially mesa just burns&crashes when old mesa runs on a newer kernel with support for a chip that mesa doesn't know about? > Anyway, I'm still leaning towards the answer being: this is not an > etnaviv regression caused by NPU, it's a longstanding generic Mesa > issue for which the answer is to fix the known fragility. If the above is correct, then yes I think we should just fix mesa. Feels like the breakage is too obviously there, and that's all we'll do unless the screaming gets too loud. -Sima -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch
