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

From: Oded Gabbay
Date: Wed Sep 16 2020 - 02:37:18 EST


On Wed, Sep 16, 2020 at 9:25 AM Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Tue, Sep 15, 2020 at 11:49:12PM +0300, Oded Gabbay wrote:
> > On Tue, Sep 15, 2020 at 11:42 PM David Miller <davem@xxxxxxxxxxxxx> wrote:
> > >
> > > From: Oded Gabbay <oded.gabbay@xxxxxxxxx>
> > > Date: Tue, 15 Sep 2020 20:10:08 +0300
> > >
> > > > This is the second version of the patch-set to upstream the GAUDI NIC code
> > > > into the habanalabs driver.
> > > >
> > > > The only modification from v2 is in the ethtool patch (patch 12). Details
> > > > are in that patch's commit message.
> > > >
> > > > Link to v2 cover letter:
> > > > https://lkml.org/lkml/2020/9/12/201
> > >
> > > I agree with Jakub, this driver definitely can't go-in as it is currently
> > > structured and designed.
> > Why is that ?
> > Can you please point to the things that bother you or not working correctly?
> > I can't really fix the driver if I don't know what's wrong.
> >
> > In addition, please read my reply to Jakub with the explanation of why
> > we designed this driver as is.
> >
> > And because of the RDMA'ness of it, the RDMA
> > > folks have to be CC:'d and have a chance to review this.
> > As I said to Jakub, the driver doesn't use the RDMA infrastructure in
> > the kernel and we can't connect to it due to the lack of H/W support
> > we have
> > Therefore, I don't see why we need to CC linux-rdma.
> > I understood why Greg asked me to CC you because we do connect to the
> > netdev and standard eth infrastructure, but regarding the RDMA, it's
> > not really the same.
>
> Ok, to do this "right" it needs to be split up into separate drivers,
> hopefully using the "virtual bus" code that some day Intel will resubmit
> again that will solve this issue.
Hi Greg,
Can I suggest an alternative for the short/medium term ?

In an earlier email, Jakub said:
"Is it not possible to move the files and still build them into a single
module?"

I thought maybe that's a good way to progress here ?
First, split the content to Ethernet and RDMA.
Then move the Ethernet part to drivers/net but build it as part of
habanalabs.ko.
Regarding the RDMA code, upstream/review it in a different patch-set
(maybe they will want me to put the files elsewhere).

What do you think ?

>
> That will allow you to put the network driver portion in drivers/net/
> and split the code up into the proper different pieces easier.
>
> I recommend grabbing the virtual bus code from the archives and looking
> at that for how this can be done. Now that you are part of Intel, I'm
> sure that the internal-Intel-Linux-kernel-review-process can kick in and
> those developers can help you out. If not, let me know, so I can go
> kick them :)
>
> As for the RDMA stuff, yeah, you should look at the current RDMA
> interfaces and verify that those really do not work for you here, and
> then document why that is in your patch submission.
ok, will do that.

Thanks,
Oded
>
> thanks,
>
> greg k-h