On 26.1.2016 13:11, Arnd Bergmann wrote: > On Tuesday 26 January 2016 10:59:12 Michal Simek wrote: >>>> diff --git a/drivers/pci/host/pcie-xilinx.c b/drivers/pci/host/pcie-xilinx.c >>>> index 3e3757f..1981948 100644 >>>> --- a/drivers/pci/host/pcie-xilinx.c >>>> +++ b/drivers/pci/host/pcie-xilinx.c >>>> @@ -92,7 +92,12 @@ >>>> #define ECAM_DEV_NUM_SHIFT 12 >>>> >>>> /* Number of MSI IRQs */ >>>> -#define XILINX_NUM_MSI_IRQS 128 >>>> +#define XILINX_NUM_MSI_IRQS 128 >>>> +#ifdef CONFIG_ARM >>>> +#define TOT_NR_IRQS XILINX_NUM_MSI_IRQS >>>> +#else >>>> +#define TOT_NR_IRQS (NR_IRQS + XILINX_NUM_MSI_IRQS) >>>> +#endif >>> >>> Something looks wrong here in the microblaze variant. What does NR_IRQS >>> have to do with it? >> >> Arnd: What was the story regarding NR_IRQS? >> I remember some discussion about it but just forget. >> >> Default value in include/asm-generic/irq.h is 64. >> Current value is 32 because microblaze primary interrupt controller is >> axi_intc core which has up to 32 input lines. > > The value in asm-generic is completely arbitrary, it's just something > that happens to work for a number of the simpler architectures. > > Traditionally, there is a a fixed NR_IRQS which defines the maximum > number of interrupts that can be used, and each irqchip has a fixed > start offset below that number. > > On modern systems, you have CONFIG_SPARSE_IRQ, which lets an irqchip > allocate its own interrupts, without an upper limit. This is more > flexible and avoids preallocating space for all irq_desc instances, > so it saves memory. ok. That was the story. I will look if there is any issue to enable SPARSE_IRQ for Microblaze. I also need to move intc driver out of arch. Thanks, Michal -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
