On 2020-03-25 14:31, Jiaxun Yang wrote:
于 2020年3月25日 GMT+08:00 下午10:15:16, Marc Zyngier <maz@xxxxxxxxxx> 写到:
On 2020-03-25 13:59, Jiaxun Yang wrote:
[...]
So probably we can use legacy domain when MIPS IRQ BASE is in the
range of legacy IRQ
and switch to simple domain when it's not in that range?
No, see below.
Here in Loongson systems IRQ 0-15 is occupied by I8259 so I did
this
hack.
Well, if you have to consider which Linux IRQ gets assigned,
then your platform is definitely not ready for non-legacy
irqdomains. Just stick to legacy for now until you have removed
all the code that knows the hwirq mapping.
Thanks.
So I have to allocate irq_desc here in driver manually?
No, you are probably better off just dropping this patch, as MIPS
doesn't seem to be ready for a wholesale switch to virtual interrupts.
It can't work without this patch.
Legacy domain require IRQ number within 0-15
however it's already occupied by i8259 or "HTPIC" driver.
Previously Loongson even didn't enable IRQ domain so it's not a
problem.
Then your platform is breaking some fundamental assumption that the rest
of the MIPS architecture seem to rely on. You could test for the base
IRQ being 0 and create a legacy domain in this case, but that's really
a horrible hack.
I'm pretty worried about having to address this just 4 days away from
the merge window TBH, as this code hasn't been in -next at all.
That's really Thomas' call, but I'm not very enthusiastic.
M.
--
Jazz is not dead. It just smells funny...
