From: Frank Rowand <frank.rowand@sony.com>
Date: Sat, 30 Oct 2021 01:10:39 +0000 (-0500)
Subject: of: unittest: document intentional interrupt-map provider build warning
X-Git-Tag: block-5.16-2021-11-13~72^2~4
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=9526565591b8db3d363be21a03b66b20575039a2;p=linux-block.git

of: unittest: document intentional interrupt-map provider build warning

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@sony.com>
Link: https://lore.kernel.org/r/20211030011039.2106946-1-frowand.list@gmail.com
Signed-off-by: Rob Herring <robh@kernel.org>
---

diff --git a/drivers/of/unittest-data/tests-interrupts.dtsi b/drivers/of/unittest-data/tests-interrupts.dtsi
index 9b60a549f502..ecc74dbcc373 100644
--- a/drivers/of/unittest-data/tests-interrupts.dtsi
+++ b/drivers/of/unittest-data/tests-interrupts.dtsi
@@ -31,6 +31,21 @@
 
 			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-interrupt_map 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 @@
 
 			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 c12bcb5cca60..481ba8682ebf 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);