Hi, Marc, On Fri, Sep 11, 2020 at 3:45 PM Marc Zyngier <maz@xxxxxxxxxx> wrote: > > On 2020-09-11 04:24, Huacai Chen wrote: > > Hi, Marc, > > > > On Thu, Sep 10, 2020 at 6:10 PM Marc Zyngier <maz@xxxxxxxxxx> wrote: > >> > >> On 2020-09-09 05:09, Huacai Chen wrote: > >> > Modernized Loongson64 uses a hierarchical organization for interrupt > >> > controllers (INTCs), all INTC nodes (not only leaf nodes) need some IRQ > >> > numbers. This means 280 (i.e., NR_IRQS_LEGACY + NR_MIPS_CPU_IRQS + 256) > >> > is not enough to represent all interrupts, so let's increase NR_IRQS to > >> > 320. > >> > > >> > Cc: stable@xxxxxxxxxxxxxxx > >> > Signed-off-by: Huacai Chen <chenhc@xxxxxxxxxx> > >> > --- > >> > arch/mips/include/asm/mach-loongson64/irq.h | 2 +- > >> > 1 file changed, 1 insertion(+), 1 deletion(-) > >> > > >> > diff --git a/arch/mips/include/asm/mach-loongson64/irq.h > >> > b/arch/mips/include/asm/mach-loongson64/irq.h > >> > index f5e362f7..0da3017 100644 > >> > --- a/arch/mips/include/asm/mach-loongson64/irq.h > >> > +++ b/arch/mips/include/asm/mach-loongson64/irq.h > >> > @@ -7,7 +7,7 @@ > >> > /* cpu core interrupt numbers */ > >> > #define NR_IRQS_LEGACY 16 > >> > #define NR_MIPS_CPU_IRQS 8 > >> > -#define NR_IRQS (NR_IRQS_LEGACY + NR_MIPS_CPU_IRQS + 256) > >> > +#define NR_IRQS 320 > >> > > >> > #define MIPS_CPU_IRQ_BASE NR_IRQS_LEGACY > >> > >> Why are you hardcoding a random value instead of bumping the constant > >> in NR_IRQS? > > Because INTCs can organized in many kinds of hierarchy, we cannot use > > constants to define a accurate value, but 320 is big enough. > > You're not answering my question. You have a parameterized NR_IRQS, and > you're turning it into an absolute constant. Why? I.e: > > #define NR_IRQS (NR_IRQS_LEGACY + NR_MIPS_CPU_IRQS + 296) > > And why 320? Why not 512? or 2^15? OK, I know, I will define a NR_MAX_MIDDLE_IRQS and then define NR_IRQS as (NR_IRQS_LEGACY + NR_MIPS_CPU_IRQS + NR_MAX_MIDDLE_IRQS + 256) > > As for a "modernized" setup, the fact that you are not using SPARSE_IRQ > is pretty backward. I have discussed this with Jiaxun, and he said that there are some difficulties to use SPARSE_IRQ. Huacai > > M. > -- > Jazz is not dead. It just smells funny...
