[PATCH v3 2/3] perf/smmuv3: Add a MODULE_SOFTDEP() to indicate dependency on SMMU

[John Garry]

On 29/01/2021 15:12, Robin Murphy wrote:
> On 2021-01-27 11:32, Zhen Lei wrote:
>> The MODULE_SOFTDEP() gives user space a hint of the loading sequence. And
>> when command "modprobe arm_smmuv3_pmu" is executed, the arm_smmu_v3.ko is
>> automatically loaded in advance.
> 
> Why do we need this? If probe order doesn't matter when both drivers are 
> built-in, why should module load order?
> 
> TBH I'm not sure why we even have a Kconfig dependency on ARM_SMMU_V3, 
> given that the drivers operate completely independently :/

Can that Kconfig dependency just be removed? I think that it was added 
under the idea that there is no point in having the SMMUv3 PMU driver 
without the SMMUv3 driver.

However even on that basis it seems broken, as we cannot have 
ARM_SMMU_V3=m + ARM_SMMU_V3_PMU=y.