Re: [PATCH v4 0/7] firmware: smccc: Add basic SMCCC v1.2 + ARCH_SOC_ID support

[Sudeep Holla <sudeep.holla@arm.com>]

On Thu, May 21, 2020 at 10:17:39AM +0100, Will Deacon wrote:
> On Thu, May 21, 2020 at 11:06:23AM +0200, Arnd Bergmann wrote:
> > On Thu, May 21, 2020 at 10:11 AM Sudeep Holla <sudeep.holla@arm.com> wrote:
> > > Indeed, it is also last patch in the series. However if Arnd is happy
> > > with the sysfs names, we can move to generic code later without breaking
> > > anything.
> > >
> > > We need not revert or drop it now. I will leave that to you or Arnd to
> > > decide. Just that it may be too late to get acks for all the soc sysfs
> > > drivers in time for v5.8
> > >
> > > I am fine if you want to drop the last patch.
> > 
> > Ok, let's drop that patch then and make sure we do something that
> > everyone is happy with later on. I'm already in favor of adding
> > a more reliable soc_device instance based on this, but we need to
> > be sure we don't screw up the contents of the attributes when we
> > can't change them later.
> > 
> > > > > >> drivers/firmware/smccc/smccc.c:14:13: warning: no previous prototype for function 'arm_smccc_version_init' [-Wmissing-prototypes]
> > > > > void __init arm_smccc_version_init(u32 version, enum arm_smccc_conduit conduit)
> > > > > ^
> > > > > drivers/firmware/smccc/smccc.c:14:1: note: declare 'static' if the
> > > > > function is not intended to be used outside of this translation unit
> > > > > void __init arm_smccc_version_init(u32 version, enum arm_smccc_conduit conduit)
> > > >
> > > > I saw that when I applied the patches, but since the function is called from
> > > > another compilation unit (psci/psci.o), I just ignored it as we have loads
> > > > of these already and it only screams if you build with W=1.
> > > >
> > >
> > > /me confused. Do you need the fix for this warning or you are happy to ignore?
> > 
> > I want a fix for that, as I hope we can eventually turn this warning on by
> > default and stop playing whack-a-mole when they come up. Most of these
> > warnings are harmless, but occasionally the prototypes don't match exactly
> > and cause real bugs depending on the configuration, and ensuring both
> > sides include a common header file is an easy way to make it work
> > more reliably.
> > 
> > Note that the warning should come up for either W=1 or C=1, and I also
> > think that
> > new code should generally be written sparse-clean and have no warnings with
> > 'make C=1' as a rule.
> 
> Fair enough. Is anybody working on a tree-wide sweep for this, like we've
> done for other things such as zero-length arrays? If so, I can start
> enforcing this in the arch code as well (I haven't been so far, even though
> I do run sparse on every commit).
> 
> Anyway, I've dropped the last patch from the branch, and we can put a fix
> for the missing prototype on top.
> 

Thanks Will, sorry for the trouble. Though I can send the fix for the
missing prototype right away, I would like to get my clang setup working
as an opportunity. clang-8 that I have is failing vanilla v5.7-rc6
when expanding arm_smccc_1_1_*

-- 
Regards,
Sudeep