Commit a9ecdc0f authored by Florian Fainelli's avatar Florian Fainelli Committed by Grant Likely
Browse files

of/irq: Fix lookup to use 'interrupts-extended' property first 



In case the Device Tree blob passed by the boot agent supplies both an
'interrupts-extended' and an 'interrupts' property in order to allow for
older kernels to be usable, prefer the new-style 'interrupts-extended'
property which conveys a lot more information.

This allows us to have bootloaders willingly maintaining backwards
compatibility with older kernels without entirely deprecating the
'interrupts' property.

Update the bindings documentation to describe a situation where both the
'interrupts-extended' and the 'interrupts' property are present, and
which one takes precedence over the other.

Cc: stable@vger.kernel.org # 3.13+
Acked-by: default avatarRob Herring <robh@kernel.org>
Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarGrant Likely <grant.likely@linaro.org>
parent b951f9dc

Documentation/devicetree/bindings/interrupt-controller/interrupts.txt

+7 −5
Original line number Diff line number Diff line
@@ -4,11 +4,13 @@ Specifying interrupt information for devices 
1) Interrupt client nodes

-------------------------



Nodes that describe devices which generate interrupts must contain an either an

"interrupts" property or an "interrupts-extended" property. These properties

contain a list of interrupt specifiers, one per output interrupt. The format of

the interrupt specifier is determined by the interrupt controller to which the

interrupts are routed; see section 2 below for details.

Nodes that describe devices which generate interrupts must contain an

"interrupts" property, an "interrupts-extended" property, or both. If both are

present, the latter should take precedence; the former may be provided simply

for compatibility with software that does not recognize the latter. These

properties contain a list of interrupt specifiers, one per output interrupt. The

format of the interrupt specifier is determined by the interrupt controller to

which the interrupts are routed; see section 2 below for details.



  Example:

	interrupt-parent = <&intc1>;

drivers/of/irq.c

+9 −8
Original line number Diff line number Diff line
@@ -301,16 +301,17 @@ int of_irq_parse_one(struct device_node *device, int index, struct of_phandle_ar 
	/* Get the reg property (if any) */

	addr = of_get_property(device, "reg", NULL);



	/* Get the interrupts property */

	intspec = of_get_property(device, "interrupts", &intlen);

	if (intspec == NULL) {

		/* Try the new-style interrupts-extended */

	/* Try the new-style interrupts-extended first */

	res = of_parse_phandle_with_args(device, "interrupts-extended",

					"#interrupt-cells", index, out_irq);

		if (res)

			return -EINVAL;

	if (!res)

		return of_irq_parse_raw(addr, out_irq);

	}



	/* Get the interrupts property */

	intspec = of_get_property(device, "interrupts", &intlen);

	if (intspec == NULL)

		return -EINVAL;



	intlen /= sizeof(*intspec);



	pr_debug(" intspec=%d intlen=%d\n", be32_to_cpup(intspec), intlen);

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