From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752769AbbIKMYq (ORCPT ); Fri, 11 Sep 2015 08:24:46 -0400 Received: from mezzanine.sirena.org.uk ([106.187.55.193]:60049 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751696AbbIKMYo (ORCPT ); Fri, 11 Sep 2015 08:24:44 -0400 Date: Fri, 11 Sep 2015 13:24:23 +0100 From: Mark Brown To: Tomeu Vizoso Cc: linux-kernel@vger.kernel.org, Rob Herring , Stephen Warren , Javier Martinez Canillas , Thierry Reding , "Rafael J. Wysocki" , linux-arm-kernel@lists.infradead.org, Dmitry Torokhov , devicetree@vger.kernel.org, Linus Walleij , linux-acpi@vger.kernel.org, Arnd Bergmann , Greg Kroah-Hartman Message-ID: <20150911122423.GS12027@sirena.org.uk> References: <1441628627-5143-1-git-send-email-tomeu.vizoso@collabora.com> <1441628627-5143-22-git-send-email-tomeu.vizoso@collabora.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="VP5QyDw/Nx1A2h9y" Content-Disposition: inline In-Reply-To: <1441628627-5143-22-git-send-email-tomeu.vizoso@collabora.com> X-Cookie: You are fairminded, just and loving. User-Agent: Mutt/1.5.23 (2014-03-12) X-SA-Exim-Connect-IP: 146.200.61.82 X-SA-Exim-Mail-From: broonie@sirena.org.uk Subject: Re: [PATCH v4 21/22] driver core: Start processing deferred probes earlier 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 --VP5QyDw/Nx1A2h9y Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Sep 07, 2015 at 02:23:46PM +0200, Tomeu Vizoso wrote: > Some initcalls in the late level assume that some devices will have > already probed without explicitly checking for that. >=20 > After the recent move to defer most device probes when they are > registered, pressure increased in the late initcall level. >=20 > By starting the processing of the deferred queue in device_initcall_sync > we increase the chances that the initcalls mentioned before will find > the devices they depend on to have already probed. Which cases do we have that are outside the driver model and thus affected by this? USB gadgets are one case I'm aware of, and cpufreq is still problematic. I'm wondering if it might be tractable to address the actual problems with the remaining reliance on init ordering here. I'm also wondering if we might end up running into situations where this makes the problem with havinng to defer probes more of an issue on some systems - since we start trying earlier while we are still doing our first pass initialisation we could end up deferring some device then retrying it a bunch of times while going through the earlier phases of init as we continue to register more devices. --VP5QyDw/Nx1A2h9y Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBCAAGBQJV8sf3AAoJECTWi3JdVIfQgrkH/1pUEr4SDBM77gU9koOCBWi6 ltw8MMtiBchWI8mRM1H+eikB2MQfuoKqGux+4/VKTef34K9zuMFNyGAl5KMyNhcc wKU4wAMEi8KCgn5exQWQE7G1/pviyvnxGFSuHF9CLB0fSyqU7DUFLaaF86kz7RSA JqZJAVHgDXeDXa/gbooODSnq5atV+hQ75JtfGoYxOA8V+680BkfT4SB2tJ7l3kVi lBh0D35eRNaGMu2JSz+KpdlfGAO7C89oB+19LhOcXaVn03VsxUp/OfDt8HBnkvqa 8k5+aXnlCq9Xjq8QRGtUGYuoBppJ0w7kQJWXRPirXbBxRpDpfphvv21j3wukonU= =vXhR -----END PGP SIGNATURE----- --VP5QyDw/Nx1A2h9y--