On 2020-09-11 09:43, Huacai Chen wrote:
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)
What does MIDDLE_IRQS mean? Please name it to something that actually
relates to its usage...
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.
It'd be worth considering putting some efforts there...
M.
--
Jazz is not dead. It just smells funny...
