Hi Leon, On Mon, Jul 22, 2024 at 01:44:07PM +0300, Leon Romanovsky wrote: > On Mon, Jul 22, 2024 at 11:53:17AM +0300, Laurent Pinchart wrote: > > On Mon, Jul 22, 2024 at 10:31:19AM +0300, Leon Romanovsky wrote: > > > On Sun, Jul 21, 2024 at 10:25:30PM +0300, Laurent Pinchart wrote: > > > > On Tue, Jul 09, 2024 at 03:15:13PM -0700, Dan Williams wrote: > > > > > James Bottomley wrote: > > > > > > > The upstream discussion has yielded the full spectrum of positions on > > > > > > > device specific functionality, and it is a topic that needs cross- > > > > > > > kernel consensus as hardware increasingly spans cross-subsystem > > > > > > > concerns. Please consider it for a Maintainers Summit discussion. > > > > > > > > > > > > I'm with Greg on this ... can you point to some of the contrary > > > > > > positions? > > > > > > > > > > This thread has that discussion: > > > > > > > > > > http://lore.kernel.org/0-v1-9912f1a11620+2a-fwctl_jgg@xxxxxxxxxx > > > > > > > > > > I do not want to speak for others on the saliency of their points, all I > > > > > can say is that the contrary positions have so far not moved me to drop > > > > > consideration of fwctl for CXL. > > > > > > > > > > Where CXL has a Command Effects Log that is a reasonable protocol for > > > > > making decisions about opaque command codes, and that CXL already has a > > > > > few years of experience with the commands that *do* need a Linux-command > > > > > wrapper. > > > > > > > > > > Some open questions from that thread are: what does it mean for the fate > > > > > of a proposal if one subsystem Acks the ABI and another Naks it for a > > > > > device that crosses subsystem functionality? Would a cynical hardware > > > > > response just lead to plumbing an NVME admin queue, or CXL mailbox to > > > > > get device-specific commands past another subsystem's objection? > > > > > > > > My default answer would be to trust the maintainers of the relevant > > > > subsystems (or try to convince them when you disagree :-)). > > > > > > You know, trust is a two-way street. If you want to trust maintainers, > > > they need to trust others as well. The situation where one maintainer > > > says "I don't trust you, so I will not allow you and other X maintainers > > > to do Y" is not a healthy situation. > > > > > > > Not only should they know the technical implications best, they should also have > > > > a good view of the whole vertical stack, and the implications of > > > > pass-through for their ecosystem. > > > > > > It is wishful thinking. It is clearly not true for large subsystems > > > and/or complex devices. > > > > Are you saying that kernel communities behind large subsystems for > > complex devices generally have no idea about what they're doing ? Or > > that in a small number of particular cases those communities are > > clueless ? Or does that apply to just the maintainer, not the whole > > subsystem core developers ? I'd like to better understand the scale of > > your claim here. > > I don't know how you jumped from saying "the maintainers of the relevant > subsystems" to "kernel communities". I'm talking about maintainers, not > communities. I wasn't too sure, so that's why I asked. I have also not been very precise in my previous e-mails. When I mentioned trusting maintainers, I meant trusting the combined knowledge of the relevant maintainer(s) and core developer(s) for a subsystem. The number of people that this covers, and how they collectively reach agreements, very much depends on subsystems. > There is no way to know everything about everything. In large subsystems, > the stack above kernel is so vast, which makes it impossible to know all > use cases. This is why some words (... good ... whole ...) in your sentence > are not accurate. > > So the idea that one maintainer somehow equal to the whole community and > this person can block something for other members of the larger community > is overreaching. -- Regards, Laurent Pinchart
