Re: [PATCH v6 00/20] gpio: cdev: add uAPI v2

From: Shuah Khan
Date: Tue Sep 08 2020 - 15:55:11 EST

On 9/4/20 7:02 AM, Bartosz Golaszewski wrote:
On Fri, Sep 4, 2020 at 2:52 PM Kent Gibson <warthog618@xxxxxxxxx> wrote:

On Thu, Sep 03, 2020 at 04:37:50PM +0800, Kent Gibson wrote:
On Thu, Sep 03, 2020 at 10:02:04AM +0200, Bartosz Golaszewski wrote:
On Mon, Aug 31, 2020 at 5:21 AM Kent Gibson <warthog618@xxxxxxxxx> wrote:


To me it looks good, just a couple nits here and there and some questions.

I think it's worth deciding whether we want to keep the selftests in
tools/testing/selftests/gpio/ and then maybe consider porting
gpio-mockup-chardev.c to V2 or simply outsource it entirely to

Ooops - I wasn't even aware they existed - though it had crossed my mind
that the kernel should have some selftests somewhere - I use the libgpiod
tests, from my libgpiod port, and my own Go based test suite for my testing,
as well as some smoke tests with the tools/gpio.

The libgpiod tests only cover v1 equivalent functionality, while my Go
tests cover the complete uAPI, and both v1 and v2.

It would be good for the kernel to at least have some smoke tests to
confirm basic functionality, even thorough testing is left to a
userspace library. So the existing tests should be ported to v2, though
should also retain the v1 tests if v1 is still compiled in.

I've got a v7 ready to submit that includes a couple of patches for the
gpio-mockup selftests (their primary purpose appears to be testing the
mockup module, rather than the GPIO ABI), but I now notice that the
selftests/gpio section of the tree has a different maintainer:

scripts/ 0021-selftests-gpio-port-to-GPIO-uAPI-v2.patch
Bamvor Jian Zhang <bamv2005@xxxxxxxxx> (maintainer:GPIO MOCKUP DRIVER)
Shuah Khan <shuah@xxxxxxxxxx> (maintainer:KERNEL SELFTEST FRAMEWORK)
linux-gpio@xxxxxxxxxxxxxxx (open list:GPIO MOCKUP DRIVER)
linux-kselftest@xxxxxxxxxxxxxxx (open list:KERNEL SELFTEST FRAMEWORK)
linux-kernel@xxxxxxxxxxxxxxx (open list)

Bamvor, Shuah: do you still have interest in maintaining these, or can
we update MAINTAINERS?

I maintain kselftests and gpio selftest falls under that. Please send
selftest patches to me so I can review them.

As for the gpio mock driver and test itself, you will have to wait for
Bamvor to respond.

The v7 patch up to that point restores the functions that the selftests
are using so that they build and run again.

This test has been problematic because of its dependency on tools/gpio.

So I should hold off on the selftest patches and submit them separately
after the GPIO changes are in?

Please send me the selftest patches. Also see the comments in
selftests/Makefile about excluding the gpio test from default run.

-- Shuah