From: Felix Fietkau <nbd@nbd.name> Date: Thu, 19 Jan 2017 12:14:44 +0100 Subject: [PATCH] MIPS: Lantiq: Fix cascaded IRQ setup With the IRQ stack changes integrated, the XRX200 devices started emitting a constant stream of kernel messages like this: [ 565.415310] Spurious IRQ: CAUSE=0x1100c300 This appears to be caused by IP0 firing for some reason without being handled. Fix this by setting up IP2-6 as a proper chained IRQ handler and calling do_IRQ for all MIPS CPU interrupts. Cc: john@phrozen.org Cc: stable@vger.kernel.org Signed-off-by: Felix Fietkau <nbd@nbd.name> --- --- a/arch/mips/lantiq/irq.c +++ b/arch/mips/lantiq/irq.c @@ -271,6 +271,11 @@ static void ltq_hw5_irqdispatch(void) DEFINE_HWx_IRQDISPATCH(5) #endif +static void ltq_hw_irq_handler(struct irq_desc *desc) +{ + ltq_hw_irqdispatch(irq_desc_get_irq(desc) - 2); +} + #ifdef CONFIG_MIPS_MT_SMP void __init arch_init_ipiirq(int irq, struct irqaction *action) { @@ -315,23 +320,19 @@ static struct irqaction irq_call = { asmlinkage void plat_irq_dispatch(void) { unsigned int pending = read_c0_status() & read_c0_cause() & ST0_IM; - unsigned int i; + int irq; - if ((MIPS_CPU_TIMER_IRQ == 7) && (pending & CAUSEF_IP7)) { - do_IRQ(MIPS_CPU_TIMER_IRQ); - goto out; - } else { - for (i = 0; i < MAX_IM; i++) { - if (pending & (CAUSEF_IP2 << i)) { - ltq_hw_irqdispatch(i); - goto out; - } - } + if (!pending) { + spurious_interrupt(); + return; } - pr_alert("Spurious IRQ: CAUSE=0x%08x\n", read_c0_status()); -out: - return; + pending >>= CAUSEB_IP; + while (pending) { + irq = fls(pending) - 1; + do_IRQ(MIPS_CPU_IRQ_BASE + irq); + pending &= ~BIT(irq); + } } static int icu_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw) @@ -356,11 +357,6 @@ static const struct irq_domain_ops irq_d .map = icu_map, }; -static struct irqaction cascade = { - .handler = no_action, - .name = "cascade", -}; - int __init icu_of_init(struct device_node *node, struct device_node *parent) { struct device_node *eiu_node; @@ -392,7 +388,7 @@ int __init icu_of_init(struct device_nod mips_cpu_irq_init(); for (i = 0; i < MAX_IM; i++) - setup_irq(i + 2, &cascade); + irq_set_chained_handler(i + 2, ltq_hw_irq_handler); if (cpu_has_vint) { pr_info("Setting up vectored interrupts\n");