Re: [PATCH v3 00/14] Adding GAUDI NIC code to habanalabs driver

[Oded Gabbay]

On Sat, Sep 19, 2020 at 11:30 AM Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Sat, Sep 19, 2020 at 11:20:03AM +0300, Leon Romanovsky wrote:
> > On Sat, Sep 19, 2020 at 08:40:20AM +0200, Greg Kroah-Hartman wrote:
> > > On Fri, Sep 18, 2020 at 03:19:05PM +0300, Leon Romanovsky wrote:
> > > > > So we do have an open-source library called hl-thunk, which uses our
> > > > > driver and indeed that was part of the requirement.
> > > > > It is similar to libdrm.
> > > > > Here is the link:
> > > > > https://github.com/HabanaAI/hl-thunk
> > > >
> > > > Are you kidding?
> > > >
> > > > This is mirror of some internal repository that looks like dumpster
> > > > with ChangeId, internal bug tracker numbers, not part of major OS
> > > > distributions.
> > > >
> > > > It is not open-source library and shows very clear why you chose
> > > > to upstream your driver through driver/misc/ tree.
> > >
> > > It is an open source library, as per the license and the code
> > > availability.  What more is expected here?
> >
> > So can I fork iproute2, add bunch of new custom netlink UAPIs and expect
> > Dave to merge it after I throw it on github?
>
> Don't be silly, that's not the case here at all and you know that.
>
> > > No distro has to pick it up, that's not a requirement for kernel code,
> > > we have many kernel helper programs that are not in distros.  Heck, udev
> > > took a long time to get into distros, does that mean the kernel side of
> > > that interface should never have been merged?
> > >
> > > I don't understand your complaint here, it's not our place to judge the
> > > code quality of userspace libraries, otherwise we would never get any
> > > real-work done :)
> >
> > My main complaint is that you can't imagine merging code into large
> > subsystems (netdev, RDMA, DRM? e.t.c) without being civil open-source
> > citizen. It means use of existing user-space libraries/tools and/or
> > providing new ones that will be usable for everyone.
>
> Agreed.
>
> > In this case, we have some custom char device with library that is not
> > usable for anyone else and this is why drivers/misc/ is right place.
>
> Also agreed.
>
> > While we are talking about real-work, it is our benefit to push companies
> > to make investment into ecosystem and not letting them to find an excuse
> > for not doing it.
>
> So why are you complaining about a stand-alone driver that does not have
> any shared subsystems's userspace code to control that driver?
>
> Yes, when integrating into other subsystems (i.e. networking and rdma),
> they should use those common subsystems interfaces, no one is arguing
> that at all.
Hi Greg,
It's probably heresy, but why do I need to integrate into the RDMA subsystem ?
I understand your reasoning about networking (Ethernet) as the driver
connects to the kernel networking stack (netdev), but with RDMA the
driver doesn't use or connect to anything in that stack. If I were to
support IBverbs and declare that I support it, then of course I would
need to integrate to the RDMA subsystem and add my backend to
rdma-core.
But we don't do that so why am I being forced to support IBverbs ?
Forcing GAUDI to use the RDMA stack and IBverbs is like swatting flies
with a sledgehammer.
I do hope that in future devices we will support it natively and of
course then we will integrate as requested, but for GAUDI it is just a
huge overkill IMHO.

Thanks,
Oded
>
> totally lost,
>
> greg k-h