Hi, Marc,
On Fri, Sep 11, 2020 at 3:50 PM Marc Zyngier maz@kernel.org wrote:
On 2020-09-11 05:13, Huacai Chen wrote:
Hi, Marc,
On Thu, Sep 10, 2020 at 6:08 PM Marc Zyngier maz@kernel.org wrote:
On 2020-09-09 05:09, Huacai Chen wrote:
Reserve legacy LPC irqs (0~15) to avoid spurious interrupts.
How can they be spurious? Why are they enabled the first place?
This looks like you are papering over a much bigger issue.
The spurious interrupts are probably occurred after kdump and the irq number is in legacy LPC ranges. I think this is because the old kernel doesn't (and it can't) disable devices properly so there are stale interrupts in the kdump case.
I don't really understand why the old kernel can't turn the interrupts off. Most architectures are able t, why not yours?
Finally, why don't you just shut these interrupts off the first place in the interrupt controller init? Adding a whole lot of kernel data structures as a band-aid doesn't strike me as the best possible idea. Not to mention that if they keep firing, all you are doing is adding extra overhead.
After tests, I found that the previous patch (patch 2 in this series) can avoid most spurious interrupts and kdump can work, so I will send V2 to drop this patch.
Huacai
M.-- Jazz is not dead. It just smells funny...