On Wed, Oct 23, 2013 at 12:58 PM, Thierry Reding <thierry.reding@xxxxxxxxx> wrote: > On Wed, Oct 23, 2013 at 01:34:50PM -0600, Jason Gunthorpe wrote: >> On Wed, Oct 23, 2013 at 08:59:10PM +0200, Thierry Reding wrote: >> >> > > I'd say yes. Going from unstable to stable is quite a step for a binding >> > > and that should be visible and worth a patch IMO. Also, when looking at >> > > a DTS file or some driver code, it will avoid >> > > confusion/misinterpretation if one can see immediately the status of a >> > > binding. >> > >> > Yes, I fully agree. It might look like churn, but I think this could >> > actually be a part of the formal process to stabilize a binding. It >> > would be final step of that process, actually. >> >> I actually think this makes things worse. >> >> Ostensibly the purpose of stable DT is to allow the DT and kernel to >> be separate, so you should minimize the churn in the DTs, and they >> should trend to stable. > > Well, I do think that stable DT has benefits. And quite frankly I think > the majority of bindings will eventually converge to some stable state > anyway, if only because active development stops. In an ideal world that > would be when a product ships. > > So this proposal isn't so much about making a decision for stable or > experimental DT, but rather about giving users a choice. If they are > willing to live with the additional "burden" of updating the DTB every > once in a while, then they can enable the option and get additional > functionality. If they don't want any part of that, they can just leave > the option disabled and only get the parts that are stable. > >> Having a flag day where someone goes and churns the DT to remove a !, >> and then changes the kernel so all old DTs with a ! won't work at all >> makes this whole thing seem kinda contrary to the basic motivating >> premis. > > No. Matching doesn't include the ! marker. So if you remove it from DTS > files and/or drivers, the only thing that goes away is the warning at > runtime. Feature-wise there should be no difference. > >> Also, what happens during development? If you incompatibly change the >> binding you should change the name, so maybe <version>!marvell,foo is >> the way to go. >> >> v1 of the binding is 1!marvell,foo - version 2 is 2!marvell,foo, etc. >> [I'm a random bystander -- I don't really know anything about DT.] This sounds awfully like the -moz, -webkit, etc. CSS property selectors. They are AFAICT nearly universally considered to have been a mistake. --Andy -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
