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. Thanks
