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.
Acked-by: Rob Herring <robh@xxxxxxxxxx>
Signed-off-by: Brian Norris <computersforpeace@xxxxxxxxx>
Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
---
Changes in v2:
- added Brian's update to the binding
- added Rob's hack based on the initial patch
- slightly reworked the comment about drivers/of/irq.c to specify which
property we look up first
.../bindings/interrupt-controller/interrupts.txt | 12 +++++++-----
drivers/of/irq.c | 17 +++++++++--------
2 files changed, 16 insertions(+), 13 deletions(-)
diff --git a/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt b/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
index 1486497a24c1..ce6a1a072028 100644
--- a/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+++ b/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
@@ -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>;
diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 3e06a699352d..1471e0a223a5 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -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);
+ /* Try the new-style interrupts-extended first */
+ res = of_parse_phandle_with_args(device, "interrupts-extended",
+ "#interrupt-cells", index, out_irq);
+ if (!res)
+ return of_irq_parse_raw(addr, out_irq);
+
/* Get the interrupts property */
intspec = of_get_property(device, "interrupts", &intlen);
- if (intspec == NULL) {
- /* Try the new-style interrupts-extended */
- res = of_parse_phandle_with_args(device, "interrupts-extended",
- "#interrupt-cells", index, out_irq);
- if (res)
- return -EINVAL;
- return of_irq_parse_raw(addr, out_irq);
- }
+ if (intspec == NULL)
+ return -EINVAL;
+
intlen /= sizeof(*intspec);
pr_debug(" intspec=%d intlen=%d\n", be32_to_cpup(intspec), intlen);
--
1.9.1
--
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