[RFC PATCH v3] irqchip: Add support for tango interrupt router

[Mason]

On 17/07/2017 17:36, Mason wrote:

> This controller maps 128 input lines to 24 output lines.
> The output lines are routed to GIC SPI 0 to 23.
> This driver muxes LEVEL_HIGH IRQs onto output line 0,
> and gives every EDGE_RISING IRQ a dedicated output line.
> ---
> I think the driver is mostly finished. It works without
> errors for my basic use-cases.

I spotted a problem. Output lines are allocated
for edge interrupts in tango_set_type() but they
are never released. So if we insmod/rmmod modules
in a loop, we will run out of output lines.

It seems set_type() is not the right place for an
allocation. Perhaps that should be done in tango_map()?

I'll try to trace the code to figure out when the
unmap function is called, as well.

> There is one required feature missing:
> suspend/resume support.
> Should it be a separate patch, or just squashed
> into this patch?

That question still stands.

Regards.