From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pantelis Antoniou Subject: Re: ACPI vs DT at runtime Date: Fri, 22 Nov 2013 13:00:03 +0100 Message-ID: <97692EF2-013E-4E4B-BC16-E0915D67EFEC@antoniou-consulting.com> References: <20131115095717.GC1709@e106331-lin.cambridge.arm.com> <20131118150052.GC24408@sirena.org.uk> <20131119091216.GA4412@netboy> <20131120064056.GB5272@netboy> <20131121192136.GA16735@n2100.arm.linux.org.uk> <20131121204704.E4487C40753@trevor.secretlab.ca> Mime-Version: 1.0 (Apple Message framework v1085) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8BIT Return-path: In-Reply-To: Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Catalin Marinas Cc: Grant Likely , Russell King - ARM Linux , Richard Cochran , Olof Johansson , Jon Masters , Mark Brown , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org Hi On Nov 22, 2013, at 12:43 PM, Catalin Marinas wrote: > On 21 November 2013 20:47, Grant Likely wrote: >> On Thu, 21 Nov 2013 19:21:36 +0000, Russell King - ARM Linux wrote: >>> On Wed, Nov 20, 2013 at 07:40:57AM +0100, Richard Cochran wrote: >>>> Now, I never saw any proclamation or discussion about "DT is in flux" >>>> on the arm list. If I had, I surely would have complained, and loudly. >>>> AFAICT, this decision was made in rather private circles, but you talk >>>> as if this was abundantly clear. *It was not.* >>> >>> DT has been discussed several times over this year alone, which >>> included discussions about the stability of bindings. Various >>> people in those threads (including myself) have put their views >>> forward. >>> >>> My position has been that if an interface ends up being published in a >>> -final kernel, then it is part of the ABI, because a -final kernel is >>> an end-product. It's a final release which says "we've done the >>> development, it's finished for users use." If it's not then it shouldn't >>> be in a -final kernel, or if it has to be there for development purposes, >>> it needs to be hidden behind a "this is in development" label. > > +1 > >>> I've said that several times in the DT discussions and I believe >>> basically been ignored. Frankly, I've said my bit and I've given up >>> caring. >> >> Umm. Not sure why you feel ignored. We're absolutely going for stability >> now. > > What I was hoping for is a better way to enforce this by taking the > dts files out of the kernel. I think that's the point where the > bindings can become ABI. In the meantime we rely on contributors and > reviewers making sure backwards compatibility is preserved. But I > guess we'll eventually get there. > As one that's going to be dealing with this, please don't take the DTS files from the kernel. If you do this, I can guarantee that within a year almost no ARM board using DT will boot a mainline kernel. The reason is that vendors have enough trouble (and failing) tracking a single tree, adding yet another will just end to the vendor trees as far as the eye can see. Maybe, maybe, EVMs from silicon vendors will still boot, but I doubt any other customer board will work. > -- > Catalin > -- > To unsubscribe from this list: send the line "unsubscribe devicetree" in > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > More majordomo info at http://vger.kernel.org/majordomo-info.html Regards -- Pantelis -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: panto@antoniou-consulting.com (Pantelis Antoniou) Date: Fri, 22 Nov 2013 13:00:03 +0100 Subject: ACPI vs DT at runtime In-Reply-To: References: <20131115095717.GC1709@e106331-lin.cambridge.arm.com> <20131118150052.GC24408@sirena.org.uk> <20131119091216.GA4412@netboy> <20131120064056.GB5272@netboy> <20131121192136.GA16735@n2100.arm.linux.org.uk> <20131121204704.E4487C40753@trevor.secretlab.ca> Message-ID: <97692EF2-013E-4E4B-BC16-E0915D67EFEC@antoniou-consulting.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi On Nov 22, 2013, at 12:43 PM, Catalin Marinas wrote: > On 21 November 2013 20:47, Grant Likely wrote: >> On Thu, 21 Nov 2013 19:21:36 +0000, Russell King - ARM Linux wrote: >>> On Wed, Nov 20, 2013 at 07:40:57AM +0100, Richard Cochran wrote: >>>> Now, I never saw any proclamation or discussion about "DT is in flux" >>>> on the arm list. If I had, I surely would have complained, and loudly. >>>> AFAICT, this decision was made in rather private circles, but you talk >>>> as if this was abundantly clear. *It was not.* >>> >>> DT has been discussed several times over this year alone, which >>> included discussions about the stability of bindings. Various >>> people in those threads (including myself) have put their views >>> forward. >>> >>> My position has been that if an interface ends up being published in a >>> -final kernel, then it is part of the ABI, because a -final kernel is >>> an end-product. It's a final release which says "we've done the >>> development, it's finished for users use." If it's not then it shouldn't >>> be in a -final kernel, or if it has to be there for development purposes, >>> it needs to be hidden behind a "this is in development" label. > > +1 > >>> I've said that several times in the DT discussions and I believe >>> basically been ignored. Frankly, I've said my bit and I've given up >>> caring. >> >> Umm. Not sure why you feel ignored. We're absolutely going for stability >> now. > > What I was hoping for is a better way to enforce this by taking the > dts files out of the kernel. I think that's the point where the > bindings can become ABI. In the meantime we rely on contributors and > reviewers making sure backwards compatibility is preserved. But I > guess we'll eventually get there. > As one that's going to be dealing with this, please don't take the DTS files from the kernel. If you do this, I can guarantee that within a year almost no ARM board using DT will boot a mainline kernel. The reason is that vendors have enough trouble (and failing) tracking a single tree, adding yet another will just end to the vendor trees as far as the eye can see. Maybe, maybe, EVMs from silicon vendors will still boot, but I doubt any other customer board will work. > -- > Catalin > -- > To unsubscribe from this list: send the line "unsubscribe devicetree" in > the body of a message to majordomo at vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html Regards -- Pantelis