Re: [PATCH 1/2] PCI: Add pci_bus_specific_read_dev_vendor_id() to workaround PCI switch specific issues prior to accessing newly added endpoint

[Alex Williamson <alex.williamson@redhat.com>]

On Thu, 26 Apr 2018 15:32:00 -0400
James Puthukattukaran <james.puthukattukaran@oracle.com> wrote:

> On 04/26/2018 02:26 AM, kbuild test robot wrote:
> > Hi James,
> > 
> > Thank you for the patch! Yet something to improve:
> > 
> > [auto build test ERROR on pci/next]
> > [also build test ERROR on v4.17-rc2 next-20180424]
> > [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
> > 
> > url:    https://github.com/0day-ci/linux/commits/James-Puthukattukaran/PCI-SUpport-to-workaround-bus-level-HW-issues/20180426-092305
> > base:   https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git next
> > config: ia64-allnoconfig (attached as .config)
> > compiler: ia64-linux-gcc (GCC) 7.2.0
> > reproduce:
> >         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> >         chmod +x ~/bin/make.cross
> >         # save the attached .config to linux build tree
> >         make.cross ARCH=ia64 
> > 
> > All errors (new ones prefixed by >>):
> > 
> >    drivers/pci/probe.o: In function `pci_bus_read_dev_vendor_id':  
> >>> probe.c:(.text+0x3e02): undefined reference to `pci_bus_specific_read_dev_vendor_id'  
> 
> Alex/Sinan -
> 
> Would it be an acceptable fix for this problem?
> 
> 
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -2097,6 +2097,13 @@ static bool pci_bus_wait_crs(struct pci_bus *bus, int devfn, u32 *l,
>  	return true;
>  }
>  
> +int __weak pci_bus_specific_read_dev_vendor_id(struct pci_bus *bus, int devfn, 
> +					u32 *l, int timeout)
> +{
> +	return -ENOTTY;
> +}
> +
> +

Close, but I'd suggest following the example set by other quirks,
generally there's a stub definition of it in pci.h when !#defined
CONFIG_PCI_QUIRKS.  See for example pci_dev_specific_acs_enabled().
Thanks,

Alex

>  bool pci_bus_generic_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l,
>  				int timeout)
>  {
> 
> 
> I ran the repro steps and it completes without issues. In addition, I will fix the typos Alex pointed out in the last submission and resubmit.
> thanks
> James