linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Cc: Dmitry Osipenko <digetx@gmail.com>,
	Thierry Reding <thierry.reding@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Stephen Boyd <sboyd@kernel.org>, Tony Lindgren <tony@atomide.com>,
	Arnd Bergmann <arnd@arndb.de>, Paul Burton <paul.burton@mips.com>,
	John Crispin <john@phrozen.org>,
	"open list:BROADCOM NVRAM DRIVER" <linux-mips@vger.kernel.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	linux-m68k <linux-m68k@lists.linux-m68k.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-tegra <linux-tegra@vger.kernel.org>,
	linux-clk <linux-clk@vger.kernel.org>,
	"open list:TI ETHERNET SWITCH DRIVER (CPSW)" 
	<linux-omap@vger.kernel.org>
Subject: Re: [PATCH v1] kbuild: Disable compile testing if HAVE_LEGACY_CLK enabled
Date: Tue, 25 May 2021 14:19:01 +0200	[thread overview]
Message-ID: <CAMuHMdW_G259Nwx1EEf38h0AcVH8yjmjqp9Mh-vQ4LJJMzD8Dg@mail.gmail.com> (raw)
In-Reply-To: <f12b4622-6cea-ac65-2d94-f50a85c29215@canonical.com>

Hi Krzysztof,

On Tue, May 25, 2021 at 2:04 PM Krzysztof Kozlowski
<krzysztof.kozlowski@canonical.com> wrote:
> On 24/05/2021 08:39, Dmitry Osipenko wrote:
> > 24.05.2021 11:54, Geert Uytterhoeven пишет:
> >> On Mon, May 24, 2021 at 1:26 AM Dmitry Osipenko <digetx@gmail.com> wrote:
> >>> There are couple older platforms that can't be compile-tested because they
> >>> partially implement CLK API. It causes build failure of kernel drivers due
> >>> to the missing symbols of the unimplemented part of CLK API.
> >>>
> >>> These platforms are: ARM EP93XX, ARM OMAP1, m68k ColdFire, MIPS AR7,
> >>>                      MIPS Ralink.
> >>>
> >>> Disable compile-testing for HAVE_LEGACY_CLK=y.
> >>>
> >>> Reported-by: kernel test robot <lkp@intel.com>
> >>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> >>
> >> Thanks for your patch!
> >>
> >>> --- a/init/Kconfig
> >>> +++ b/init/Kconfig
> >>> @@ -131,7 +131,7 @@ config INIT_ENV_ARG_LIMIT
> >>>
> >>>  config COMPILE_TEST
> >>>         bool "Compile also drivers which will not load"
> >>> -       depends on HAS_IOMEM
> >>> +       depends on HAS_IOMEM && !HAVE_LEGACY_CLK
> >>
> >> That sounds a bit drastic to me.  Usually we just try to implement the
> >> missing functionality, or provide stubs.
> >> Which functions are missing?
> >
> > Everything that belongs to CONFIG_COMMON_CLK needs stubs.
> >
> > That is everything under CONFIG_HAVE_CLK [1], excluding functions
> > belonging to clk-devres.o and clk-bulk.o [2]. The HAVE_LEGACY_CLK
> > selects HAVE_CLK, but the COMMON_CLK is under HAVE_CLK too.
> >
> > [1]
> > https://elixir.bootlin.com/linux/v5.13-rc3/source/include/linux/clk.h#L786
> > [2]
> > https://elixir.bootlin.com/linux/v5.13-rc3/source/drivers/clk/Makefile#L3
> >
> > This problem is repeated over and over again for the past years. Some
> > maintainers are adding "depends on COMMON_CLK" for COMPILE_TEST of each
> > driver, but this doesn't solve the root of the problem, and thus, it's
> > constantly reoccurring.
> >
> > Recently Krzysztof Kozlowski added couple more clk stubs for MIPS, but
> > still lots of stubs are missing. Some platforms don't have any stubs at
> > all and apparently nobody cares to fix them.
> >
> > There 3 possible solutions:
> >
> > 1. Factor out COMMON_CLK from HAVE_LEGACY_CLK, if this is possible
> > 2. Build stubs universally, maybe using weak functions.
>
> I vote for this one - global stubs.

Yep.

> Or for a new one:
> 4. Disable COMPILE_TEST for specific platforms (mentioned in commit
> msg). Eventually could be like:
> config RALINK
>         depends !COMPILE_TEST || (COMPILE_TEST && COMMON_CLK)

That's a neat idea!

Of course there's a fifth option:

5. Convert legacy platforms to COMMON_CLK.

Which is already happening for ARM EP93XX.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

  reply	other threads:[~2021-05-25 12:19 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-23 23:25 Dmitry Osipenko
2021-05-24  8:54 ` Geert Uytterhoeven
2021-05-24 12:39   ` Dmitry Osipenko
2021-05-25 12:03     ` Krzysztof Kozlowski
2021-05-25 12:19       ` Geert Uytterhoeven [this message]
2021-05-25 21:29         ` Dmitry Osipenko
2021-05-26  0:39           ` Randy Dunlap
2021-05-28  9:27             ` Arnd Bergmann
2021-05-28  9:24     ` Arnd Bergmann

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CAMuHMdW_G259Nwx1EEf38h0AcVH8yjmjqp9Mh-vQ4LJJMzD8Dg@mail.gmail.com \
    --to=geert@linux-m68k.org \
    --cc=arnd@arndb.de \
    --cc=digetx@gmail.com \
    --cc=john@phrozen.org \
    --cc=jonathanh@nvidia.com \
    --cc=krzysztof.kozlowski@canonical.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-clk@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-m68k@lists.linux-m68k.org \
    --cc=linux-mips@vger.kernel.org \
    --cc=linux-omap@vger.kernel.org \
    --cc=linux-tegra@vger.kernel.org \
    --cc=paul.burton@mips.com \
    --cc=sboyd@kernel.org \
    --cc=thierry.reding@gmail.com \
    --cc=tony@atomide.com \
    --subject='Re: [PATCH v1] kbuild: Disable compile testing if HAVE_LEGACY_CLK enabled' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).