Re: [PATCH v5 1/4] resource: Move reparent_resources() to kernel/resource.c and make it public

[Baoquan He <bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

Hi Andy,

On 06/12/18 at 05:24pm, Andy Shevchenko wrote:
> On Tue, Jun 12, 2018 at 5:20 PM, Andy Shevchenko
> <andy.shevchenko-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> >> Hmm, I just copied it from arch/powerpc/kernel/pci-common.c. The
> >> function interface expects an integer returned value, not sure what a
> >> real error codes look like, could you give more hints? Will change
> >> accordingly.
> >
> > I briefly looked at the code and error codes we have, so, my proposal
> > is one of the following
> 
> >  - use -ECANCELED (not the best choice for first occurrence here,
> > though I can't find better)
> 
> Actually -ENOTSUPP might suit the first case (although the actual
> would be something like -EOVERLAP, which we don't have)

Sorry for late reply, and many thanks for your great suggestion.

I am fine to use -ENOTSUPP as the first returned value, and -ECANCELED
for the 2nd one. Or define an enum as you suggested inside the function
or in header file.

Or use -EBUSY for the first case because existing resource is
overlapping but not fully contained by 'res'; and -EINVAL for
the 2nd case since didn't find any one resources which is contained by
'res', means we passed in a invalid resource. 

All is fine to me, I can repost with each of them.

Thanks
Baoquan

> 
> >  - use positive integers (or enum), like
> >   #define RES_REPARENTED 0
> >   #define RES_OVERLAPPED 1
> >   #define RES_NOCONFLICT 2
> >
> >
> >>> > +               if (firstpp == NULL)
> >>> > +                       firstpp = pp;
> >>> > +       }
> >>>
> >>> > +       if (firstpp == NULL)
> >>> > +               return -1;      /* didn't find any conflicting entries? */
> >>>
> >>> Ditto.
> >
> > Ditto.
> >
> >>>
> >>> > +}
> >>> > +EXPORT_SYMBOL(reparent_resources);
> >
> > --
> > With Best Regards,
> > Andy Shevchenko
> 
> 
> 
> -- 
> With Best Regards,
> Andy Shevchenko