From: Frank Rowand <frank.rowand@xxxxxxxx> Geert reports that gpio hog nodes are not properly processed when the gpio hog node is added via an overlay reply and provides an RFC patch to fix the problem [1]. Add a unittest that shows the problem. Unittest will report "1 failed" test before applying Geert's RFC patch and "0 failed" after applying Geert's RFC patch. I did not have a development system for which it would be easy to experiment with applying an overlay containing a gpio hog, so I instead created this unittest that uses a fake gpio node. Some tests in the devicetree unittests result in printk messages from the code being tested. It can be difficult to determine whether the messages are the result of unittest or are potentially reporting bugs that should be fixed. The most recent example of a person asking whether to be concerned about these messages is [2]. Patch 2 adds annotations for all messages triggered by unittests, except KERN_DEBUG messages. (KERN_DEBUG is a special case due to the possible interaction of CONFIG_DYNAMIC_DEBUG.) The annotations added in patch 2/2 add a small amount of verbosity to the console output. I have created a proof of concept tool to explore (1) how test harnesses could use the annotations and (2) how to make the resulting console output easier to read and understand as a human being. The tool 'of_unittest_expect' is available at https://github.com/frowand/dt_tools The format of the annotations is expected to change when unittests are converted to use the kunit infrastructure when the broader testing community has an opportunity to discuss the implementation of annotations of test triggered messages. [1] https://lore.kernel.org/linux-devicetree/20191230133852.5890-1-geert+renesas@xxxxxxxxx/ [2] https://lore.kernel.org/r/6021ac63-b5e0-ed3d-f964-7c6ef579cd68@xxxxxxxxxx Frank Rowand (2): of: unittest: add overlay gpio test to catch gpio hog problem of: unittest: annotate warnings triggered by unittest drivers/of/unittest-data/Makefile | 8 +- drivers/of/unittest-data/overlay_gpio_01.dts | 23 + drivers/of/unittest-data/overlay_gpio_02a.dts | 16 + drivers/of/unittest-data/overlay_gpio_02b.dts | 16 + drivers/of/unittest-data/overlay_gpio_03.dts | 23 + drivers/of/unittest-data/overlay_gpio_04a.dts | 16 + drivers/of/unittest-data/overlay_gpio_04b.dts | 16 + drivers/of/unittest.c | 630 ++++++++++++++++++++++++-- 8 files changed, 717 insertions(+), 31 deletions(-) create mode 100644 drivers/of/unittest-data/overlay_gpio_01.dts create mode 100644 drivers/of/unittest-data/overlay_gpio_02a.dts create mode 100644 drivers/of/unittest-data/overlay_gpio_02b.dts create mode 100644 drivers/of/unittest-data/overlay_gpio_03.dts create mode 100644 drivers/of/unittest-data/overlay_gpio_04a.dts create mode 100644 drivers/of/unittest-data/overlay_gpio_04b.dts -- Frank Rowand <frank.rowand@xxxxxxxx>
