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

[Frank Rowand <frowand.list@gmail.com>]

On 2/19/20 3:56 PM, Rob Herring wrote:
> 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.

I agree.  I would like to see my patches applied, showing the test fail,
immediately followed by Geert's fix.  So my series should not go in
until Geert's patch is ready.

> 
>>
>> [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

But my changelog claimed that I fixed that, isn't that
good enough?  :-)

/me pulls big brown paper bag over head.

And the same for all the issues you point out below, for the
second patch version in a row.

I'll re-spin on 5.6-rc1 and truly include the fixes.

-Frank


> 
> 
>> +		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";
>> +	};
>> +};
>