Received-SPF: softfail (google.com: domain of transitioning linux-kernel-owner@vger.kernel.org does not designate 23.128.96.19 as permitted sender) client-ip=23.128.96.19;
MIME-Version: 1.0
References: <20220513064952.3610672-1-gerg@linux-m68k.org> <CAMuHMdVWRM7U9_SxbtDUE0a-sB5_PDiO2009Cu3QKMP3wNc=yw@mail.gmail.com>
 <2532419a-812b-c2de-ef56-849ec7dc16bc@linux-m68k.org>
In-Reply-To: <2532419a-812b-c2de-ef56-849ec7dc16bc@linux-m68k.org>
From:   Arnd Bergmann <arnd@arndb.de>
Date:   Fri, 13 May 2022 14:59:24 +0200
Message-ID: <CAK8P3a3RuOTidFpW7diHekJ6POV20SBb5PhSF943Ju1xAtOxNw@mail.gmail.com>
Subject: Re: [PATCH] m68knommu: fix undefined reference to `mach_get_rtc_pll'
To:     Greg Ungerer <gerg@linux-m68k.org>
Cc:     Geert Uytterhoeven <geert@linux-m68k.org>,
        "Linux/m68k" <linux-m68k@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Arnd Bergmann <arnd@arndb.de>,
        kernel test robot <lkp@intel.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Fri, May 13, 2022 at 2:25 PM Greg Ungerer <gerg@linux-m68k.org> wrote:
> On 13/5/22 17:12, Geert Uytterhoeven wrote:
> > read_persistent_clock64() uses mach_hwclk(), which is provided by
> > both setup_mm.c and setup_no.c, so it's always available?> Albeit not populated by coldfire or nommu platform code, so I see
> > the point in depending on MMU (no nommu Amiga support yet ;-).
>
> Yes, exactly. And even worse is that on ColdFire platforms it
> is never set, so will be the startup value of NULL. It is called
> without checking for NULL in both of rtc_generic_get_time() and
> rtc_generic_set_time().

I think that's ok because rtc_generic_{get,set}_time is only called
from the rtc_generic driver, but that is not registered when mach_hwclk()
is NULL.

With your patch to add the CONFIG_MMU check, you can actually
remove the mach_hwclk() symbol from setup_no.c, and move the
remaining RTC related symbols from setup_mm.c into the #ifdef.

       Arnd