RE: [PATCH v3 04/18] irqchip: add nps Internal and external irqchips

From: Noam Camus
Date: Wed Dec 02 2015 - 10:09:00 EST


>From: Marc Zyngier [mailto:marc.zyngier@xxxxxxx]
>Sent: Tuesday, December 01, 2015 3:29 PM

> + interrupt source. The value shall be 1.

>So you never have to encode the interrupt trigger type? Do you only support edge or level?
I Always use level sensitive.

> +
> +#define NPS_GIM_P_EN 0x100 /* Peripheral interrupts source enable */
> +#define NPS_GIM_P_BLK 0x118 /* Peripheral interrupts blocking for sources */

>>Are these the interrupts the peripherals are using? If yes, they really have nothing to do here...
I will move this from here
>> + __asm__ __volatile__ (
>> + " .word %0\n"
>> + :
>> + : "i"(CTOP_INST_RSPI_GIC_0_R12)
>> + : "memory");

>Silly question: why cannot you just write the actual instruction instead of shoving the instruction like this? Also, .inst would be more appropriate...
[Noam Camus] Since this is instruction that yet is not part of up-streamed binutils of ARC. Now ARC maintainer can build our kernel with generic ARC toolchain.

>> +static int nps400_irq_map(struct irq_domain *d, unsigned int irq,
>> + irq_hw_number_t hw)
>> +{
>> + switch (irq) {
>> + case TIMER0_IRQ:
>> +#if defined(CONFIG_SMP)
>> + case IPI_IRQ:
>> +#endif
>> + irq_set_chip_and_handler(irq, &nps400_irq_chip_percpu,
>> + handle_percpu_irq);
>> + break;
>> + default:
>> + irq_set_chip_and_handler(irq, &nps400_irq_chip_fasteoi,
>> + handle_fasteoi_irq);
>> + break;
>> + }

>No. This is just wrong. Either you get per interrupt information from the device tree to configure the interrupt the right way, or you have different interrupt controllers for each device.
I am not sure how you want me to get it from DTB? Please refer to some reference.

>But using the Linux irq number is always wrong. You should only consider the hwirq.
I will change

> +
> + nps400_root_domain = irq_domain_add_legacy(node, NR_CPU_IRQS, 0, 0,
> + &nps400_irq_ops, NULL);

>And that's why you can get away with the above horror. Don't use legacy domains. This stuff is by no mean legacy.
So what is my alternative here?

-Noam
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