Dears, yeah, I have known some reason on it: * not call "mips_cpu_irq_init" in function "arch_init_irq" * and did not use "set_irq_chip_and_handler" * before I only setup the "chip" with code "irq_desc[i].chip = &irq_type;", but it is for old kernel(2.6.19) so new code is: void __init arch_init_irq(void) { int i; mips_cpu_irq_init(); for (i = 0; i < 32; ++i) { set_irq_chip_and_handler(i, &irq_type, handle_level_irq); } }