Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965337AbaGCJxJ (ORCPT ); Thu, 3 Jul 2014 05:53:09 -0400 Received: from service87.mimecast.com ([91.220.42.44]:51810 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965074AbaGCJxG convert rfc822-to-8bit (ORCPT ); Thu, 3 Jul 2014 05:53:06 -0400 Date: Thu, 3 Jul 2014 10:53:02 +0100 From: Liviu Dudau To: Tanmay Inamdar Cc: Arnd Bergmann , linux-pci , Bjorn Helgaas , Catalin Marinas , Will Deacon , Benjamin Herrenschmidt , linaro-kernel , Grant Likely , Sinan Kaya , Jingoo Han , Kukjin Kim , Suravee Suthikulanit , LKML , Device Tree ML , LAKML , patches Subject: Re: [PATCH v8 2/9] pci: Export find_pci_host_bridge() function. Message-ID: <20140703095302.GY2173@e106497-lin.cambridge.arm.com> References: <1404240214-9804-1-git-send-email-Liviu.Dudau@arm.com> <1404240214-9804-3-git-send-email-Liviu.Dudau@arm.com> <7101568.8DVJFku5jp@wuerfel> MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/1.5.22 (2013-10-16) X-OriginalArrivalTime: 03 Jul 2014 09:53:03.0913 (UTC) FILETIME=[95353990:01CF96A4] X-MC-Unique: 114070310530307801 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 02, 2014 at 09:43:41PM +0100, Tanmay Inamdar wrote: > On Wed, Jul 2, 2014 at 12:12 PM, Arnd Bergmann wrote: > > On Wednesday 02 July 2014 11:06:38 Tanmay Inamdar wrote: > >> On Tue, Jul 1, 2014 at 11:43 AM, Liviu Dudau wrote: > >> > This is a useful function and we should make it visible outside the > >> > generic PCI code. Export it as a GPL symbol. > >> > > >> > Signed-off-by: Liviu Dudau > >> > Tested-by: Tanmay Inamdar > >> > --- > >> > drivers/pci/host-bridge.c | 3 ++- > >> > 1 file changed, 2 insertions(+), 1 deletion(-) > >> > > >> > diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c > >> > index 0e5f3c9..36c669e 100644 > >> > --- a/drivers/pci/host-bridge.c > >> > +++ b/drivers/pci/host-bridge.c > >> > @@ -16,12 +16,13 @@ static struct pci_bus *find_pci_root_bus(struct pci_bus *bus) > >> > return bus; > >> > } > >> > > >> > -static struct pci_host_bridge *find_pci_host_bridge(struct pci_bus *bus) > >> > +struct pci_host_bridge *find_pci_host_bridge(struct pci_bus *bus) > >> > { > >> > struct pci_bus *root_bus = find_pci_root_bus(bus); > >> > > >> > return to_pci_host_bridge(root_bus->bridge); > >> > } > >> > +EXPORT_SYMBOL_GPL(find_pci_host_bridge); > >> > >> Is there any specific reason behind making this symbol GPL? I think > >> the other functions in this file are just EXPORT_SYMBOL. Ultimately > >> companies which have non gpl Linux modules (nvidia) will face issue > >> using this API. > >> > >> The same applies to 'of_create_pci_host_bridge'. > > > > I think EXPORT_SYMBOL_GPL() is better here. The new symbols are unlikely > > to be used by a peripheral device driver, and PCI host controllers are > > already restricted by EXPORT_SYMBOL_GPL. > > > > You are right as long as the functions are not used directly. But what > if GPL functions are called indirectly. For example, 'pci_domain_nr' > implementation in Liviu's V7 series calls 'find_pci_host_bridge'. I will not be drawn into the discussion of EXPORT_SYMBOL vs EXPORT_SYMBOL_GPL() other than to say that I don't understand what is so secret in implementing a standard. I do not want to support host bridge drivers that are not open source. Best regards, Liviu > > > nvidia will certainly not do a PCI host controller driver that is not > > upstream or not GPL-compatible. > > > > Arnd > -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯ -- 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/