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

[Robin Murphy]

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 :/

Robin.

> Signed-off-by: Zhen Lei <thunder.leizhen at huawei.com>
> ---
>   drivers/perf/arm_smmuv3_pmu.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c
> index e5e505a0804fe53..9a305ac51208cd2 100644
> --- a/drivers/perf/arm_smmuv3_pmu.c
> +++ b/drivers/perf/arm_smmuv3_pmu.c
> @@ -950,6 +950,7 @@ static void __exit arm_smmu_pmu_exit(void)
>   module_exit(arm_smmu_pmu_exit);
>   
>   MODULE_DESCRIPTION("PMU driver for ARM SMMUv3 Performance Monitors Extension");
> +MODULE_SOFTDEP("pre: arm_smmu_v3");
>   MODULE_AUTHOR("Neil Leeder <nleeder at codeaurora.org>");
>   MODULE_AUTHOR("Shameer Kolothum <shameerali.kolothum.thodi at huawei.com>");
>   MODULE_LICENSE("GPL v2");
>