[coreboot] [PATCH] artecgroup/dbe62: Route ethernet adapter IRQ correctly and reduce interrupt contention problems by using different IRQs for all the interrupt lines

[ron minnich]

(I'm hoping someone will do this :-)

One issue I'm having is that the hfcpci card (or driver) can't
tolerate shared interrupts.
But we have shared interrupts on the various cs5536 boards, since we
put USB interrupt info in the table.

To allow us to have non-shared interrupts for all devices, we need to
get the USB interrupts out of the PIR table. They are not really
routed via the standard IRQ router anyway -- they are internal -- and
don't need to share interrupt #s with the other devices that are
actually routed via the interrupt routing hardware.

Put simply, having the USB f.3,4,5 devices in the PIR table works, but
is really a bit of a mistake.

OK, where do we put the IRQ info for the USB devices? In the DTS for
the cs5536.

SO in DTS for the cs5536 we need three more properties,
usbf3
usbf4
usbf5

with reasonable settings for them. Then in the chipset init code, we
need to see if these are set and, if so, set the IRQ line in the f.3,
f.4, and f.5 devices.

If this is confusing I can explain in more detail, but later, I'm
tired, and the ISDN card just locked up again. How can such a simple
driver have so many failure modes? Oh, wait, it's not simple, sigh.

but, short form: on the cs5536, USB interrupts should not be described
in the PIR table, but via settings derived from dts. They should be
initialized in cs5536 setup code, no in the PIR setup code. That will
allow us to have non-shared interrupts on the various PCI slots on,
e.g., alix1c, and allow broken drivers like hfcpci to work.

ron