[PATCH V4] powerpc/MPIC: Add get_version API both for internal and external use

[Jia Hongtao-B38951]

> -----Original Message-----
> From: Wood Scott-B07421
> Sent: Wednesday, April 10, 2013 11:20 AM
> To: Jia Hongtao-B38951
> Cc: Wood Scott-B07421; linuxppc-dev at lists.ozlabs.org;
> galak at kernel.crashing.org; Li Yang-R58472
> Subject: Re: [PATCH V4] powerpc/MPIC: Add get_version API both for
> internal and external use
> 
> On 04/09/2013 10:14:06 PM, Jia Hongtao-B38951 wrote:
> >
> >
> > > -----Original Message-----
> > > From: Wood Scott-B07421
> > > Sent: Wednesday, April 10, 2013 11:12 AM
> > > To: Jia Hongtao-B38951
> > > Cc: Wood Scott-B07421; linuxppc-dev at lists.ozlabs.org;
> > > galak at kernel.crashing.org; Li Yang-R58472
> > > Subject: Re: [PATCH V4] powerpc/MPIC: Add get_version API both for
> > > internal and external use
> > >
> > > On 04/09/2013 10:10:37 PM, Jia Hongtao-B38951 wrote:
> > > >
> > > >
> > > > > -----Original Message-----
> > > > > From: Wood Scott-B07421
> > > > > Sent: Wednesday, April 10, 2013 11:08 AM
> > > > > To: Jia Hongtao-B38951
> > > > > Cc: Wood Scott-B07421; linuxppc-dev at lists.ozlabs.org;
> > > > > galak at kernel.crashing.org; Li Yang-R58472
> > > > > Subject: Re: [PATCH V4] powerpc/MPIC: Add get_version API both
> > for
> > > > > internal and external use
> > > > >
> > > > > On 04/09/2013 10:04:44 PM, Jia Hongtao-B38951 wrote:
> > > > > > Since all the functions including mpic_alloc() and
> > mpic_init() do
> > > > the
> > > > > > check for MPIC_FSL before using fsl_mpic_get_version() I'd
> > like
> > > > to add
> > > > > > check just for fsl_mpic_primary_get_version().
> > > > > >
> > > > > > It will be like this:
> > > > > > u32 fsl_mpic_primary_get_version(void)
> > > > > > {
> > > > > >         struct mpic *mpic = mpic_primary;
> > > > > >
> > > > > >         if (mpic && (mpic->flags & MPIC_FSL))
> > > > > >                 return fsl_mpic_get_version(mpic);
> > > > > >
> > > > > >         return 0;
> > > > > > }
> > > > > >
> > > > > > Could we reach an agreement here?
> > > > >
> > > > > Is there any particular reason?  It would be more robust and
> > more
> > > > > consistent if the check were done in fsl_mpic_get_version().
> > > > >
> > > > > -Scott
> > > >
> > > > I found out that all the functions using fsl_mpic_get_version()
> > have
> > > > already done the check. Adding the check in fsl_mpic_get_version()
> > > > will cause duplicate check there. This is my consideration.
> > >
> > > Does that duplicate check cause any harm?
> > >
> > > -Scott
> >
> > No harm at all just not necessary.
> 
> Not *necessary*, but makes it more robust and more consistent.
> 
> > I wonder if I could add check in fsl_mpic_get_version() and remove
> > all the
> > check from functions in which using fsl_mpic_get_version()?
> 
> One of the two places that calls it is the place that maps thiscpuregs
> in the first place, so no. :-)

Reasonable enough.
I will just add check in fsl_mpic_get_version().

Thanks.
-Hongtao.

> 
> The check in mpic_init() for the number of timers could perhaps have
> the check removed if we're comfortable equating a version of zero with
> a non-FSL MPIC.  This really isn't something that's worth worrying
> about, though.
> 
> -Scott