Commit 10a20b34 authored Nov 12, 2021 by Marc Zyngier

of/irq: Don't ignore interrupt-controller when interrupt-map failed



Since 04128418 ("of/irq: Allow matching of an interrupt-map local
to an interrupt controller"), the irq code favors using an interrupt-map
over a interrupt-controller property if both are available, while the
earlier behaviour was to ignore the interrupt-map altogether.

However, we now end-up with the opposite behaviour, which is to
ignore the interrupt-controller property even if the interrupt-map
fails to match its input. This new behaviour breaks the AmigaOne
X1000 machine, which ships with an extremely "creative" (read:
broken) device tree.

Fix this by allowing the interrupt-controller property to be selected
when interrupt-map fails to match anything.

Fixes: 04128418 ("of/irq: Allow matching of an interrupt-map local to an interrupt controller")
Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/78308692-02e6-9544-4035-3171a8e1e6d4@xenosoft.de
Link: https://lore.kernel.org/r/20211112143644.434995-1-maz@kernel.org
Cc: Bjorn Helgaas <bhelgaas@google.com>

parent 69ea4630

drivers/of/irq.c

+16 −3

Original line number	Diff line number	Diff line
		@@ -161,9 +161,10 @@ int of_irq_parse_raw(const __be32 addr, struct of_phandle_args out_irq)
		* if it is then we are done, unless there is an
		* interrupt-map which takes precedence.
		*/
		bool intc = of_property_read_bool(ipar, "interrupt-controller");

		imap = of_get_property(ipar, "interrupt-map", &imaplen);
		if (imap == NULL &&
		of_property_read_bool(ipar, "interrupt-controller")) {
		if (imap == NULL && intc) {
		pr_debug(" -> got it !\n");
		return 0;
		}
		@@ -244,8 +245,20 @@ int of_irq_parse_raw(const __be32 addr, struct of_phandle_args out_irq)

		pr_debug(" -> imaplen=%d\n", imaplen);
		}
		if (!match)
		if (!match) {
		if (intc) {
		/*
		* The PASEMI Nemo is a known offender, so
		* let's only warn for anyone else.
		*/
		WARN(!IS_ENABLED(CONFIG_PPC_PASEMI),
		"%pOF interrupt-map failed, using interrupt-controller\n",
		ipar);
		return 0;
		}

		goto fail;
		}

		/*
		* Successfully parsed an interrrupt-map translation; copy new