Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752937Ab2EGGHR (ORCPT ); Mon, 7 May 2012 02:07:17 -0400 Received: from hqemgate04.nvidia.com ([216.228.121.35]:10187 "EHLO hqemgate04.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751820Ab2EGGHP (ORCPT ); Mon, 7 May 2012 02:07:15 -0400 X-PGP-Universal: processed; by hqnvupgp06.nvidia.com on Sun, 06 May 2012 23:06:22 -0700 Date: Mon, 7 May 2012 09:06:19 +0300 From: Hiroshi Doyu To: Stephen Warren CC: "linux-tegra@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "balbi@ti.com" , "arnd@arndb.de" , "ccross@android.com" , "olof@lixom.net" , "linux@arm.linux.org.uk" , "grant.likely@secretlab.ca" , "rob.herring@calxeda.com" , "gregkh@linuxfoundation.org" , "ohad@wizery.com" , "linus.walleij@linaro.org" , "linville@tuxdriver.com" , "myungjoo.ham@samsung.com" , "linux-kernel@vger.kernel.org" , "devicetree-discuss@lists.ozlabs.org" Subject: Re: [PATCHv3 1/4] ARM: tegra: Add Tegra AHB driver Message-ID: <20120507090619.90932b9f67a4b672abeb887f@nvidia.com> In-Reply-To: <4FA40878.7070709@wwwdotorg.org> References: <1336061147-10245-1-git-send-email-hdoyu@nvidia.com> <4FA2C34F.5060406@wwwdotorg.org> <20120504.091736.839941449020176796.hdoyu@nvidia.com> <4FA40878.7070709@wwwdotorg.org> X-Mailer: Sylpheed 3.2.0beta3 (GTK+ 2.24.6; x86_64-pc-linux-gnu) X-NVConfidentiality: public MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2053 Lines: 44 On Fri, 4 May 2012 18:48:56 +0200 Stephen Warren wrote: > On 05/04/2012 12:17 AM, Hiroshi Doyu wrote: > > Stephen Warren wrote at Thu, 3 May 2012 19:41:35 +0200: > >> On 05/03/2012 10:05 AM, Hiroshi DOYU wrote: > >>> Tegra AHB Bus conforms to the AMBA Specification (Rev 2.0) Advanced > >>> High-performance Bus (AHB) architecture. > ... > >>> +static int __init tegra_ahb_module_init(void) > >>> +{ > >>> + return platform_driver_register(&tegra_ahb_driver); > >>> +} > >>> +postcore_initcall(tegra_ahb_module_init); > >> > >> Can this be a module_init() instead of postcore_initcall()? > > > > Since this driver configures prefetch size from AHB client devices, > > it's better to make this driver available before other AHB client > > drivers get ready. So "postcore_initcall()" seems to make sense if > > there's no other better initcall. > > I believe this only affects when the driver is registered and has no > influence over when the device itself is probed. > > When booting with board files rather than DT, it was possible to > register drivers and platform devices early using various initcalls to > control the order. However, with DT, I believe all the devices are > instantiated from DT at the same time (well, one by one in whatever > order as the DT is parsed), so the time when the driver is registered > isn't relevant. > > So, if the other AHB devices really need this AHB driver to initialize > first, you'd better move all the AHB devices inside the AHB node in DT, > so that the AHB driver can influence when the children get probed. > Still, I'd suggest leaving that to a later patch, since everything > clearly works fine right now without this driver even existing. Ok, I'll use module_platform_driver(tegra_ahb_driver). These order would be revisited. -- 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/