[PATCH 1/1] of: unittest: document intentional interrupt-map provider build warning

From: frowand . list
Date: Fri Oct 29 2021 - 21:12:14 EST


From: Frank Rowand <frank.rowand@xxxxxxxx>

A recently implemented dtc compiler warning reports a dts problem
via a build warning:

drivers/of/unittest-data/tests-interrupts.dtsi:32.26-35.6: Warning (interrupt_map): /testcase-data/interrupts/intmap1: Missing '#address-cells' in interrupt-map provider

The warning will be addressed by a separate patch by suppressing the
warning for .dts files that include this .dtsi. This patch documents
why the warning is due to a deliberately incorrect .dtsi file so that
no one will fix the .dtsi file to prevent the build warning.

Signed-off-by: Frank Rowand <frank.rowand@xxxxxxxx>
---
.../of/unittest-data/tests-interrupts.dtsi | 19 +++++++++++++++++++
drivers/of/unittest.c | 6 ++++++
2 files changed, 25 insertions(+)

diff --git a/drivers/of/unittest-data/tests-interrupts.dtsi b/drivers/of/unittest-data/tests-interrupts.dtsi
index 9b60a549f502..8c8d267d4d3c 100644
--- a/drivers/of/unittest-data/tests-interrupts.dtsi
+++ b/drivers/of/unittest-data/tests-interrupts.dtsi
@@ -31,6 +31,21 @@ test_intmap0: intmap0 {

test_intmap1: intmap1 {
#interrupt-cells = <2>;
+ /*
+ * #address-cells is required
+ *
+ * The property is not provided in this node to
+ * test that the code will properly handle
+ * this case for legacy .dts files.
+ *
+ * Not having #address-cells will result in a
+ * warning from dtc starting with
+ * version v1.6.1-19-g0a3a9d3449c8
+ * The warning is suppressed by adding
+ * -Wno-interrupts_property to the Makefile
+ * for all .dts files this include this .dtsi
+ #address-cells = <1>;
+ */
interrupt-map = <0x5000 1 2 &test_intc0 15>;
};

@@ -46,6 +61,10 @@ interrupts1 {

interrupts-extended0 {
reg = <0x5000 0x100>;
+ /*
+ * Do not remove &test_intmap1 from this
+ * property - see comment in node intmap1
+ */
interrupts-extended = <&test_intc0 1>,
<&test_intc1 2 3 4>,
<&test_intc2 5 6>,
diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
index 8c056972a6dd..04bfef8f67c3 100644
--- a/drivers/of/unittest.c
+++ b/drivers/of/unittest.c
@@ -1129,6 +1129,12 @@ static void __init of_unittest_parse_interrupts_extended(void)
passed &= (args.args[1] == 14);
break;
case 6:
+ /*
+ * Tests child node that is missing property
+ * #address-cells. See the comments in
+ * drivers/of/unittest-data/tests-interrupts.dtsi
+ * nodes intmap1 and interrupts-extended0
+ */
passed &= !rc;
passed &= (args.args_count == 1);
passed &= (args.args[0] == 15);
--
Frank Rowand <frank.rowand@xxxxxxxx>