Re: linux-next: build failure after merge of the pci tree

[Bjorn Helgaas <bhelgaas@google.com>]

On Wed, Sep 26, 2018 at 9:56 AM Keith Busch <keith.busch@intel.com> wrote:
>
> On Wed, Sep 26, 2018 at 08:25:40AM -0600, Keith Busch wrote:
> > On Wed, Sep 26, 2018 at 03:00:51PM +1000, Stephen Rothwell wrote:
> > > Hi Bjorn,
> > >
> > > After merging the pci tree, today's linux-next build (powerpc allnoconfig)
> > > failed like this:
> > >
> > > ld: drivers/pci/pci.o: in function `pci_bus_error_reset':
> > > pci.c:(.text+0x5fba): undefined reference to `pci_slot_mutex'
> > > ld: pci.c:(.text+0x5fc2): undefined reference to `pci_slot_mutex'
> > >
> > > Caused by commit
> > >
> > >   131b0ca2c7b2 ("PCI/ERR: Use slot reset if available")
> > >
> > > I have applied the following hack for today (there is probably a better
> > > way):
> >
> > Thanks for the notice. Does this mean you don't have CONFIG_SYSFS? I
> > must admit I missed that connection for building slot.c.
> >
> >
> > > From: Stephen Rothwell <sfr@canb.auug.org.au>
> > > Date: Wed, 26 Sep 2018 14:55:37 +1000
> > > Subject: [PATCH] pci: move pci_slot_mutex so it is available where needed
> > >
> > > Fixes: 131b0ca2c7b2 ("PCI/ERR: Use slot reset if available")
> > > Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
> > > ---
> > >  drivers/pci/pci.c  | 2 ++
> > >  drivers/pci/slot.c | 1 -
> > >  2 files changed, 2 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> > > index 8c1e99a637d8..1fa67db6b21e 100644
> > > --- a/drivers/pci/pci.c
> > > +++ b/drivers/pci/pci.c
> > > @@ -5190,6 +5190,8 @@ static int pci_bus_reset(struct pci_bus *bus, int probe)
> > >     return ret;
> > >  }
> > >
> > > +DEFINE_MUTEX(pci_slot_mutex);
> > > +
> > >  /**
> > >   * pci_bus_error_reset - reset the bridge's subordinate bus
> > >   * @bridge: The parent device that connects to the bus to reset
> > > diff --git a/drivers/pci/slot.c b/drivers/pci/slot.c
> > > index 3da03fcc6fbf..c46d5e1ff536 100644
> > > --- a/drivers/pci/slot.c
> > > +++ b/drivers/pci/slot.c
> > > @@ -14,7 +14,6 @@
> > >
> > >  struct kset *pci_slots_kset;
> > >  EXPORT_SYMBOL_GPL(pci_slots_kset);
> > > -DEFINE_MUTEX(pci_slot_mutex);
> > >
> > >  static ssize_t pci_slot_attr_show(struct kobject *kobj,
> > >                                     struct attribute *attr, char *buf)
> > > --
> > > 2.18.0
>
> There's unfortunately second bug here when there are no slots, which
> would be the case without CONFIG_SYSFS: the slot list is empty, and the
> function just returned success, but it should have gone to the default
> secondary bus reset behavior in that case. I'll send a patch shortly.

I folded in Keith's patch for this, so you should be able to drop your
workaround, Stephen.