Vladimir Oltean 1447c63580 Revert "arm64: dts: freescale: Fix 'interrupt-map' parent address cells"
This reverts commit 869f0ec048. That
updated the expected device tree binding format for the ls-extirq
driver, without also updating the parsing code (ls_extirq_parse_map)
to the new format.

The context is that the ls-extirq driver uses the standard
"interrupt-map" OF property in a non-standard way, as suggested by
Rob Herring during review:
https://lore.kernel.org/lkml/20190927161118.GA19333@bogus/

This has turned out to be problematic, as Marc Zyngier discovered
through commit 0412841812 ("of/irq: Allow matching of an interrupt-map
local to an interrupt controller"), later fixed through commit
de4adddcbc ("of/irq: Add a quirk for controllers with their own
definition of interrupt-map"). Marc's position, expressed on multiple
opportunities, is that:

(a) [ making private use of the reserved "interrupt-map" name in a
    driver ] "is wrong, by the very letter of what an interrupt-map
    means. If the interrupt map points to an interrupt controller,
    that's the target for the interrupt."
https://lore.kernel.org/lkml/87k0g8jlmg.wl-maz@kernel.org/

(b) [ updating the driver's bindings to accept a non-reserved name for
    this property, as an alternative, is ] "is totally pointless. These
    machines have been in the wild for years, and existing DTs will be
    there *forever*."
https://lore.kernel.org/lkml/87ilvrk1r0.wl-maz@kernel.org/

Considering the above, the Linux kernel has quirks in place to deal with
the ls-extirq's non-standard use of the "interrupt-map". These quirks
may be needed in other operating systems that consume this device tree,
yet this is seen as the only viable solution.

Therefore, the premise of the patch being reverted here is invalid.
It doesn't matter whether the driver, in its non-standard use of the
property, complies to the standard format or not, since this property
isn't expected to be used for interrupt translation by the core.

This change restores LS1088A, LS2088A/LS2085A and LX2160A to their
previous bindings, which allows these systems to continue to use
external interrupt lines with the correct polarity.

Fixes: 869f0ec048 ("arm64: dts: freescale: Fix 'interrupt-map' parent address cells")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2022-03-16 19:41:14 +01:00
2022-02-06 12:20:50 -08:00

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