[PATCH V4 2/2] arm64: perf: add support for percpu pmu interrupt

[Vinayak Kale]

On Wed, Nov 20, 2013 at 11:30 PM, Will Deacon <will.deacon at arm.com> wrote:
> On Wed, Nov 20, 2013 at 05:28:50PM +0000, Vinayak Kale wrote:
>> In Will's existing code, I think he was taking care of 'no IRQ' case
>> by comparing pmu_device->num_resources. Do you think this is not
>> enough and we must enforce the check after each platform_get_irq()?
>> Existing driver code snippet as below for quick reference.
>>
>> [snip]
>> static int
>> armpmu_reserve_hardware(struct arm_pmu *armpmu)
>> {
>>         int i, err, irq, irqs;
>>         struct platform_device *pmu_device = armpmu->plat_device;
>>
>>         if (!pmu_device) {
>>                 pr_err("no PMU device registered\n");
>>                 return -ENODEV;
>>         }
>>
>>         irqs = min(pmu_device->num_resources, num_possible_cpus());
>>         if (irqs < 1) {
>>                 pr_err("no irqs for PMUs defined\n");
>>                 return -ENODEV;
>>         }
>
> This bit is fine.
>
>>         for (i = 0; i < irqs; ++i) {
>>                 err = 0;
>>                 irq = platform_get_irq(pmu_device, i);
>>                 if (irq < 0)
>>                          continue;
>
> This is a bug, which you can fix in your patch. IRQ0 isn't valid.

Okay, will fix this.