On 2021-12-31 18:13, Vladimir Oltean wrote:
Hello,
On Tue, Dec 14, 2021 at 03:58:52PM +0200, Vladimir Oltean wrote:
This reverts commit 869f0ec048dc8fd88c0b2003373bd985795179fb. 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 041284181226 ("of/irq: Allow matching of an
interrupt-map
local to an interrupt controller"), later fixed through commit
de4adddcbcc2 ("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@xxxxxxxxxx/
(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@xxxxxxxxxx/
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: 869f0ec048dc ("arm64: dts: freescale: Fix 'interrupt-map'
parent address cells")
Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
---
v1->v2: remove the other 9 patches that rename "interrupt-map" to
"fsl,extirq-map", at Marc's suggestion.
Could this patch be considered for merging in v5.16? The problem is
going to be quite a bit more severe and tricky to fix otherwise.
Thanks.
FWIW:
Acked-by: Marc Zyngier <maz@xxxxxxxxxx>
Rob, Shawn, can you please queue this as an urgent fix for 5.16?
Thanks,
M.
--
Jazz is not dead. It just smells funny...
