[PATCH] pxa168 and pxa930 build fix - plat-pxa/pmu.c dependent on ARCH_PXA for IRQ_PMU

[eric.y.miao@gmail.com (Eric Miao)]

On Tue, Jun 8, 2010 at 4:52 PM, Will Deacon <will.deacon@arm.com> wrote:
> Hi Eric,
>
>> We have different ways to handle this:
>>
>> 1. register different platform devices with different IRQs for pxa[23]xx, pxa168
>> 2. modify the IRQ at run-time to a correct one
>> 3. move the platform device registration back into arch/arm/mach-pxa/<soc>.c
>> (or arch/arm/mach-pxa/common.c) and arch/arm/mach-mmp/<soc>.c
>
> For the RealView boards, we take approach number (1). This is largely for two
> reasons:
>
> 1.) The PMU IRQ doesn't have a consistent naming scheme
> 2.) SMP RealView platforms need to have an extra resource in the
> ? ?platform_device for each CPU.
>
> However, looking at the PXA168 description and the perf-events code,
> I don't think we support the PMU anyway [see init_hw_perf_events in
> arch/arm/kernel/perf_event.c]. If the PMU present is accessible in the
> same way as one of the other supported PMUs, then it would be easy to
> add it to the perf-events code. Otherwise, a new PMU driver will need
> to be written if people want to use it.
>
> Without access to a TRM, I can't tell whether or not supporting the PMU
> is trivial, so I guess we go with option (3) for the time being.
>
>> We need to figure out if there are some other differences between these
>> PMUs (or in the future), which will make solution 3) stand out.
>
> In the future I reckon PMU devices will be memory-mapped and live inside
> components other than the CPU. PMU registration will then be highly SoC-specific.
> Perf events doesn't yet support any of this, so it depends how future-proof you
> want to be!
>

For a quick solution of the build error, I decided to pick Jonathan's
patch first. At least PMU is not tested and ever used on pxa168/910/mmp2
series at this moment. I'll work on a proper fix later, possibly a patch
merged through -devel branch instead of -fix.

>
>> >> ?arch/arm/plat-pxa/Makefile | ? ?3 ++-
>> >> ?1 files changed, 2 insertions(+), 1 deletions(-)
>> >>
>> >> diff --git a/arch/arm/plat-pxa/Makefile b/arch/arm/plat-pxa/Makefile
>> >> index 6187edf..a17cc0c 100644
>> >> --- a/arch/arm/plat-pxa/Makefile
>> >> +++ b/arch/arm/plat-pxa/Makefile
>> >> @@ -2,8 +2,9 @@
>> >> ?# Makefile for code common across different PXA processor families
>> >> ?#
>> >>
>> >> -obj-y ?:= dma.o pmu.o
>> >> +obj-y ?:= dma.o
>> >>
>> >> +obj-$(CONFIG_ARCH_PXA) ? ? ? ? += pmu.o
>> >> ?obj-$(CONFIG_GENERIC_GPIO) ? ? += gpio.o
>> >> ?obj-$(CONFIG_PXA3xx) ? ? ? ? ? += mfp.o
>> >> ?obj-$(CONFIG_ARCH_MMP) ? ? ? ? += mfp.o
>> >> --
>> >> 1.6.4.4
>
>
>