> > 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. > > This code however doesn't do either of the two on microblaze: > > + irq = pos; > +#ifdef CONFIG_MICROBLAZE > +#define TOT_NR_IRQS (NR_IRQS + XILINX_NUM_MSI_IRQS) > + irq = XILINX_NUM_MSI_IRQS + pos; #endif > + if (irq < TOT_NR_IRQS) > set_bit(pos, msi_irq_in_use); > > So you define XILINX_NUM_MSI_IRQS to mean the number of interrupts > that the xilinx_pcie_port can handle itself, but then pick a number > outside of this range by making the hwirq number something between > XILINX_NUM_MSI_IRQS and (2*XILINX_NUM_MSI_IRQS - 1), and in the > end compare it to (NR_IRQS + XILINX_NUM_MSI_IRQS), which is the > sum of two things that are not related: the total number of interrupts > including the MSIs and the number of MSI. > Agreed, I have crosschecked something's which I missed previously, NR_IRQS have nothing to do with the count, and also no need to add, irq = XILINX_NUM_MSI_IRQS + pos; in microblaze, I will remove these checks in next patch series. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
