Messages in this thread Patch in this message | | | Date | Wed, 3 Feb 2016 12:51:27 -0600 | From | Bjorn Helgaas <> | Subject | Re: [PATCH RESEND 1/3] PCI: Add fwnode_handle to pci_sysdata |
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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 <jakeo@microsoft.com> > > Cc: gregkh@linuxfoundation.org; KY Srinivasan <kys@microsoft.com>; linux- > > kernel@vger.kernel.org; devel@linuxdriverproject.org; Haiyang Zhang > > <haiyangz@microsoft.com>; 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 <asm/pci.h> > > > > > > +#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.
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