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

[Shuah Khan]

On 9/8/20 7:09 PM, Kent Gibson wrote:
> On Tue, Sep 08, 2020 at 10:04:05AM -0600, Shuah Khan wrote:
> > On 9/8/20 9:54 AM, Bartosz Golaszewski wrote:
> > > On Tue, Sep 8, 2020 at 5:24 PM Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx> wrote:
> > > > 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:
> > > > > > > > >
> > > > > > [snip]
> > > > > > > > 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
> > > > > > > > libgpiod.
> > > > > > >
> > > > > > > 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/get_maintainer.pl 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.
> > >
> > > Hi Shuah,
> > >
> > > I've been de facto maintaining gpio-mockup for a couple years now.
> > > Bamvor has been quite inactive as far as gpio testing goes. I think
> > > it's fine if you ack the selftests changes.
> >
> > That is fine. I can do quick review and Ack so you can take them
> > through gpio tree.
> >
> > > In fact: I don't want selftests to block getting V2 uAPI upstream so
> > > if that'll look like it's going to take more time then I'm for merging
> > > V2 without any changes to selftests - in the end we have tests in
> > > user-space already.
> >
> > Tests and features go through subsystem trees to avoid delays. Please
> > make sure the test doesn't break the default kselftest build/run.
> >
> > In the future it would help if you include all the maintainers on the
> > patch series, so I can review the tests from the framework angle to
> > see if they build/run correctly.
>
> To clarify, the patches have been submitted to the correct maintainers.
> While this v6, and those before, inadvertently broke the gpio selftests
> by removing code they depend on, there have been no code changes in the
> selftest tree, and so nothing for you to review.  The v7 of this series
> restored the functions that the selftests use so that they again build
> and run - still nothing for you to review.

> While I had patches for the selftests available for v7, I pulled them
> from the patch series as I didn't want to bother you or Bamvor with the
> other patches that you wouldn't be interested in.  Further, the gpio
> selftests are intended to test the gpio-mockup, as evidenced by Bamvor
> being their maintainer and the code itself.  There have been no changes
> to the mockup here, and the existing selftests remain valid without being
> ported to the latest GPIO uAPI.  Porting them to the latest uAPI, and then
> removing the resulting dead code from tools/gpio, is a nice to have that
> can wait and shouldn't block getting the uAPI changes in tree.

Thanks for the clarification.

-- Shuah