Re: [PATCH 1/2] of: unittest: add overlay gpio test to catch gpio hog problem

Rob Herring
2020-02-19T21:57:01Z

On Tue, Jan 28, 2020 at 11:46:04PM -0600, frowand.list@gmail.com wrote:
> From: Frank Rowand <frank.rowand@sony.com>
>
> 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.

What's the status of that? I don't want to leave the tests failing at
least outside of a kernel release.

>
> [1] https://lore.kernel.org/linux-devicetree/20191230133852.5890-1-geert+renesas@glider.be/
>
> Signed-off-by: Frank Rowand <frank.rowand@sony.com>
> ---
>
> There are checkpatch warnings.
> - New files are in a directory already covered by MAINTAINERS
> - The undocumented compatibles are restricted to use by unittest
> and should not be documented under Documentation
> - The printk() KERN_<LEVEL> warnings are false positives. The level
> is supplied by a define parameter instead of a hard coded constant
> - The lines over 80 characters are consistent with unittest.c style
>
> This unittest was also valuable in that it allowed me to explore
> possible issues related to the proposed solution to the gpio hog
> problem.
>
> changes since RFC:
> - fixed node names in overlays
> - removed unused fields from struct unittest_gpio_dev
> - of_unittest_overlay_gpio() cleaned up comments
> - of_unittest_overlay_gpio() moved saving global values into
> probe_pass_count and chip_request_count more tightly around
> test code expected to trigger changes in the global values
>
> 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 | 255 ++++++++++++++++++++++++++
> 8 files changed, 372 insertions(+), 1 deletion(-)
> 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
>
> diff --git a/drivers/of/unittest-data/Makefile b/drivers/of/unittest-data/Makefile
> index 9b6807065827..009f4045c8e4 100644
> --- a/drivers/of/unittest-data/Makefile
> +++ b/drivers/of/unittest-data/Makefile
> @@ -21,7 +21,13 @@ obj-$(CONFIG_OF_OVERLAY) += overlay.dtb.o \
> overlay_bad_add_dup_prop.dtb.o \
> overlay_bad_phandle.dtb.o \
> overlay_bad_symbol.dtb.o \
> - overlay_base.dtb.o
> + overlay_base.dtb.o \
> + overlay_gpio_01.dtb.o \
> + overlay_gpio_02a.dtb.o \
> + overlay_gpio_02b.dtb.o \
> + overlay_gpio_03.dtb.o \
> + overlay_gpio_04a.dtb.o \
> + overlay_gpio_04b.dtb.o
>
> # enable creation of __symbols__ node
> DTC_FLAGS_overlay += -@
> diff --git a/drivers/of/unittest-data/overlay_gpio_01.dts b/drivers/of/unittest-data/overlay_gpio_01.dts
> new file mode 100644
> index 000000000000..f039e8bce3b6
> --- /dev/null
> +++ b/drivers/of/unittest-data/overlay_gpio_01.dts
> @@ -0,0 +1,23 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/dts-v1/;
> +/plugin/;
> +
> +&unittest_test_bus {
> + #address-cells = <1>;
> + #size-cells = <0>;
> + gpio_01 {

Missing unit address:

gpio@0

> + compatible = "unittest-gpio";
> + reg = <0>;
> + gpio-controller;
> + #gpio-cells = <2>;
> + ngpios = <2>;
> + gpio-line-names = "line-A", "line-B";
> +
> + line_b {

Don't use '_'.

line-b

> + gpio-hog;
> + gpios = <2 0>;
> + input;
> + line-name = "line-B-input";
> + };
> + };
> +};
> diff --git a/drivers/of/unittest-data/overlay_gpio_02a.dts b/drivers/of/unittest-data/overlay_gpio_02a.dts
> new file mode 100644
> index 000000000000..cdafab604793
> --- /dev/null
> +++ b/drivers/of/unittest-data/overlay_gpio_02a.dts
> @@ -0,0 +1,16 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/dts-v1/;
> +/plugin/;
> +
> +&unittest_test_bus {
> + #address-cells = <1>;
> + #size-cells = <0>;
> + gpio_02 {

gpio@1

...and a few more.

> + compatible = "unittest-gpio";
> + reg = <1>;
> + gpio-controller;
> + #gpio-cells = <2>;
> + ngpios = <2>;
> + gpio-line-names = "line-A", "line-B";
> + };
> +};