Re: [PATCH] ARM: mcpm, perf/arm-cci: export mcpm_is_available

[Will Deacon]

On Tue, May 29, 2018 at 04:42:51PM +0100, Russell King - ARM Linux wrote:
> On Tue, May 29, 2018 at 04:41:20PM +0100, Will Deacon wrote:
> > Hi Russell,
> > 
> > On Tue, May 29, 2018 at 04:33:24PM +0100, Russell King - ARM Linux wrote:
> > > On Tue, May 29, 2018 at 04:30:14PM +0100, Will Deacon wrote:
> > > > Hi Arnd, Russell, [+Nico and Robin]
> > > > 
> > > > On Mon, May 28, 2018 at 05:44:36PM +0200, Arnd Bergmann wrote:
> > > > > Now that the ARM CCI PMU driver can be built as a loadable module,
> > > > > we get a link failure when MCPM is enabled:
> > > > > 
> > > > > ERROR: "mcpm_is_available" [drivers/perf/arm-cci.ko] undefined!
> > > > > 
> > > > > The simplest fix is to export that helper function.
> > > > > 
> > > > > Fixes: 8b0c93c20ef7 ("perf/arm-cci: Allow building as a module")
> > > > > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> > > > > ---
> > > > > The patch that caused this is currently part of the arm-perf/for-next/perf
> > > > > branch, it would be good to have the fix there as well.
> > > > > ---
> > > > >  arch/arm/common/mcpm_entry.c | 2 ++
> > > > >  1 file changed, 2 insertions(+)
> > > > 
> > > > I'm happy to take this via the arm perf tree if others are ok with that.
> > > > Alternatively, I can revert the offending commit if there are objections
> > > > to exporting the symbol.
> > > > 
> > > > Russell: do you any preference?
> > > 
> > > As it claims to fix 8b0c93c20ef7, which I don't have, I can't take this
> > > patch.  Do we know which tree has this?
> > 
> > Yes, sorry, it's in my for-next/perf branch:
> > 
> > https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/commit/?h=for-next/perf&id=8b0c93c20ef78f15d8b760964ff79bda7f68c610
> > 
> > which is now in -next.
> > 
> > I'm happy to take the mcpm patch on top with your ack, but if you have
> > conflicting changes (or would prefer not to export the symbol to modules)
> > then I can just revert the patch in my tree for now.
> 
> I have no changes to that file, so:
> 
> Acked-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>

Thanks, I've picked up the fix from Arnd with your Ack and will push out
this evening.

Will