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 5:37 PM, Frank Rowand wrote:
> 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.

Geert has sent a v2 patch series.

I have sent a v2 of this patch, tested with v2 of Geert's patch series.

-Frank

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