Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760100AbbKUN1k (ORCPT ); Sat, 21 Nov 2015 08:27:40 -0500 Received: from mezzanine.sirena.org.uk ([106.187.55.193]:42026 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751709AbbKUN1i (ORCPT ); Sat, 21 Nov 2015 08:27:38 -0500 Date: Sat, 21 Nov 2015 13:26:12 +0000 From: Mark Brown To: Thierry Reding Cc: Andrzej Hajda , "Rafael J. Wysocki" , Linux PM list , Greg Kroah-Hartman , Linux Kernel Mailing List , Alan Stern , Grant Likely , Rob Herring , Tomeu Vizoso , Dmitry Torokhov , Geert Uytterhoeven , Michael Turquette Message-ID: <20151121132612.GF26072@sirena.org.uk> References: <1623682.7KVblAB3KQ@vostro.rjw.lan> <564B224D.3050904@samsung.com> <20151117135549.GR31303@sirena.org.uk> <20151119131857.GF21862@ulmo.nvidia.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="udcq9yAoWb9A4FsZ" Content-Disposition: inline In-Reply-To: <20151119131857.GF21862@ulmo.nvidia.com> X-Cookie: Your domestic life may be harmonious. User-Agent: Mutt/1.5.24 (2015-08-30) X-SA-Exim-Connect-IP: 92.40.248.95 X-SA-Exim-Mail-From: broonie@sirena.org.uk Subject: Re: [RFD] Functional dependencies between devices X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: Yes (on mezzanine.sirena.org.uk) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2482 Lines: 58 --udcq9yAoWb9A4FsZ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Nov 19, 2015 at 02:18:59PM +0100, Thierry Reding wrote: > On Tue, Nov 17, 2015 at 01:55:49PM +0000, Mark Brown wrote: > > On Tue, Nov 17, 2015 at 01:49:17PM +0100, Andrzej Hajda wrote: > > > On 10/27/2015 04:24 PM, Rafael J. Wysocki wrote: > > > this scenario: > > > - many clock providers, irq domains are not provided by devices, > > That seems like something we can and possibly should change if we want. > It's not very trivial, unfortunately. I had a crack at that a long time > ago, but the problem is that these devices all need to be available very > early during boot, at which point devices aren't registered yet. With > all the progress on probe deferral and the on-demand probing work this > might be less of an issue nowadays, I haven't looked at it for quite a > while. I believe it's a lot easier to do that now but ICBW. We've started needing to put these things into firmware so that we can refer to them =66rom clients so we pretty much have to deal with it. I've not had to worry about it too much directly myself recently though. > That said, one technique I've occasionally resorted to is to have some > early code, be it one of the OF table things or an initcall, set up a > basic environment, typically using global variables (yuck!), but then > provide a proper driver that knows how to take these things over when > its time comes. That's not a perfect solution, but at least it gives you > a proper struct device to work with. Indeed, that's also how things like the console work. --udcq9yAoWb9A4FsZ Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBCAAGBQJWUHD0AAoJECTWi3JdVIfQA0gH/2h3yF+16l/YvIODQoiHkt1V PdtUR71rzy+EnxCDEkhSqmsb+kcDxSm0vdHBakTR3kRAhqI5F5Lj6aHH7tNbPfFT amhiJsrSE/ZZQFhokxUe/fUdWJgAtqUS9kv2egCI/55SBHSNbuF5kBe+0jta7kc0 FyN1XrFHjO8mfnKzk3mXpL/nF2DNWFHOuAtywkpKJ8XGg5LPnL8E6vb2UVr/REPB 0ad5lPwTlEuaCcOfmUPkmREICKwoSH8OXYbu/Peirf6nBVz2XMvs+VIrTdJJjeAD OYeDYq+ZYymwb618BAguV6RuBVdd3eYnWjTsYEX8Fu1Uukvtj0ADUYl+l/l+XdI= =xZdj -----END PGP SIGNATURE----- --udcq9yAoWb9A4FsZ-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/