Re: [PATCH RFC 07/15] pci: Add pci_probe() and pci_shutdown()

[Alexander Gordeev <agordeev@redhat.com>]

On Thu, Apr 14, 2016 at 09:45:57AM +0200, Thomas Huth wrote:
> On 11.04.2016 13:04, Alexander Gordeev wrote:
> > Cc: Thomas Huth <thuth@redhat.com>
> > Cc: Andrew Jones <drjones@redhat.com>
> > Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
> > ---
> >  lib/asm-generic/pci.h | 15 ++++++++++++++-
> >  lib/pci.c             |  1 -
> >  lib/pci.h             |  2 ++
> >  3 files changed, 16 insertions(+), 2 deletions(-)
> > 
> > diff --git a/lib/asm-generic/pci.h b/lib/asm-generic/pci.h
> > index 3fa0b2ab1fe6..175b0497ed82 100644
> > --- a/lib/asm-generic/pci.h
> > +++ b/lib/asm-generic/pci.h
> > @@ -1,4 +1,17 @@
> >  #ifndef _ASM_GENERIC_PCI_H_
> >  #define _ASM_GENERIC_PCI_H_
> > -#error need architecture specific asm/pci.h
> > +
> > +#ifndef pci_probe
> > +static inline bool pci_probe(void)
> > +{
> > +	return true;
> > +}
> > +#endif
> > +
> > +#ifndef pci_shutdown
> > +static inline void pci_shutdown(void)
> > +{
> > +}
> > +#endif
> > +
> >  #endif
> 
> What are these functions supposed to do exactly? (and why is the default
> implementation empty?) ... some comments would be really helpful here.

These two are expected to init/scan and shutdown PCI busses - something
a firmware or bios do. Only when pci_probe() succeeded all pci_* public
functions are expected functional.

They are empty, because this is default implementation. Architectures
that need initialize PCI bus should override these functions.

>  Thomas
>