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Date: Tue, 2 Apr 2024 22:20:01 +0300
From: Leon Romanovsky <leon@kernel.org>
To: Jakub Kicinski <kuba@kernel.org>
Cc: David Ahern <dsahern@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jason Gunthorpe <jgg@nvidia.com>,
	Christoph Hellwig <hch@infradead.org>,
	Saeed Mahameed <saeed@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
	Jiri Pirko <jiri@nvidia.com>, Leonid Bloch <lbloch@nvidia.com>,
	Itay Avraham <itayavr@nvidia.com>,
	Saeed Mahameed <saeedm@nvidia.com>,
	Aron Silverton <aron.silverton@oracle.com>,
	linux-kernel@vger.kernel.org,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	Andy Gospodarek <andrew.gospodarek@broadcom.com>,
	Junxian Huang <huangjunxian6@hisilicon.com>
Subject: Re: [PATCH V4 0/5] mlx5 ConnectX control misc driver
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On Mon, Apr 01, 2024 at 12:04:20PM -0700, Jakub Kicinski wrote:
> On Mon, 1 Apr 2024 21:10:33 +0300 Leon Romanovsky wrote:
> > > Sorry, I have a completely different reading of that thread.
> > > Thanks for bringing it up, tho.  
> > 
> > Different people have different opinions, and it is fine.
> 
> Agreed! I think the core of our disagreement is whether and when
> one set of people get to force their set of choices on other people.
> Far be it from me to try to force my opinions in RDMA or the kernel
> as a whole.
> 
> > > As I said multiple times I agree that configuring custom parameters
> > > in RDMA is a necessity. Junxian's approach of putting such code in
> > > the RDMA driver / subsystem is more than reasonable. Even better,
> > > it looks like the API is fairly narrowly defined.  
> > 
> > It was a tiny example, which emphasizes the need for a common way.
> > 
> > If we were listen to average RDMA driver author, we would find ourselves
> > with gazillion different sysfs knobs which do nothing except sending
> > raw data to FW. As a subsystem, we don't want to waste our time in
> > not-beneficial to the subsystem code.
> 
> No disagreement here either, there's a trade-off here between what
> you call waste of time and what I'd call fostering organic
> collaboration. Even without taking your priorities into account -
> whether reviewing device APIs is beneficial is (a) subjective, 
> (b) subsystem dependent, so you should be allowed to make your choice
> (within the bounds of Linus's trust). But what I keep arguing is that
> so should we :|

Internal device API is a different story, and I assure you that we are
very close in our views here. Probably main difference is that I'm very
lax for first user and very strict for the second one, while you are more
stricter than me even for the first one.

I gave an example from HNS for API to configure FW without any subsystem
involvement and there is no real way to push to collaboration here without
standardization.

Thanks