I'm having the exact problem that was nicely described in an earlier post regarding pre-DT kernels: Getting zeros on i.MX6 PMU counters
My kernel is 3.10.17. I can "fix" this by somewhat blindly pasting the suggested assembly snippet into the cpu_pmu_device_probe function in arch/arm/kernel/perf_event_cpu.c:
|u32 val = 0b11;|
|asm volatile("mcr p15, 0, %0, c1, c1, 1" : : "r" (val));|
I'm hoping that there is a more elegant way of doing this. Device tree item perhaps? Has anyone else run into this problem?