From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 3 Feb 2016 12:51:27 -0600 From: Bjorn Helgaas To: Jake Oshins Cc: "gregkh@linuxfoundation.org" , KY Srinivasan , "linux-kernel@vger.kernel.org" , "devel@linuxdriverproject.org" , Haiyang Zhang , "marc.zyngier@arm.com" , "bhelgaas@google.com" , "linux-pci@vger.kernel.org" Subject: Re: [PATCH RESEND 1/3] PCI: Add fwnode_handle to pci_sysdata Message-ID: <20160203185127.GE10879@localhost> References: <1454434903-1680-1-git-send-email-jakeo@microsoft.com> <1454434903-1680-2-git-send-email-jakeo@microsoft.com> <20160203182528.GB10879@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: On Wed, Feb 03, 2016 at 06:32:20PM +0000, Jake Oshins wrote: > > -----Original Message----- > > From: Bjorn Helgaas [mailto:helgaas@kernel.org] > > Sent: Wednesday, February 3, 2016 10:25 AM > > To: Jake Oshins > > Cc: gregkh@linuxfoundation.org; KY Srinivasan ; linux- > > kernel@vger.kernel.org; devel@linuxdriverproject.org; Haiyang Zhang > > ; marc.zyngier@arm.com; > > bhelgaas@google.com; linux-pci@vger.kernel.org > > Subject: Re: [PATCH RESEND 1/3] PCI: Add fwnode_handle to pci_sysdata > > > > Hi Jake, > > > > On Tue, Feb 02, 2016 at 05:41:41PM +0000, jakeo@microsoft.com wrote: > > > diff --git a/include/linux/pci.h b/include/linux/pci.h index > > > 27df4a6..cd05a8e 100644 > > > --- a/include/linux/pci.h > > > +++ b/include/linux/pci.h > > > @@ -1515,6 +1515,10 @@ static inline int pci_get_new_domain_nr(void) { > > > return -ENOSYS; } > > > > > > #include > > > > > > +#ifndef pci_root_bus_fwnode > > > +#define pci_root_bus_fwnode(bus) ((void)(bus), NULL) > > > > Huh, interesting. This is new for me; I guess the idea is that we at least > > evaluate "bus" even when pci_root_bus_fwnode isn't defined, so the > > compiler can catch egregious errors? > > > > This was a suggestion by Mark Zyngier. It made the non-x86 architectures build benignly. If you'd like it done differently, I'm open to suggestion. Something like "#define pci_root_bus_fwnode(bus) NULL" would be typical. What I'm curious about is the use of the comma operator. I'm not opposed to it; I'm just trying to understand why it makes a difference.