Re: [linux-next:master 1932/6331] drivers/phy/ralink/phy-mt7621-pci.c:341:34: warning: unused variable 'mt7621_pci_phy_ids'

[Sergio Paracuellos <sergio.paracuellos@gmail.com>]

Hi Nick,

On Wed, Jun 2, 2021 at 6:47 PM Nick Desaulniers <ndesaulniers@google.com> wrote:
>
> On Wed, Jun 2, 2021 at 3:38 AM Sergio Paracuellos
> <sergio.paracuellos@gmail.com> wrote:
> >
> > Hi,
> >
> > On Wed, Jun 2, 2021 at 12:27 PM kernel test robot <lkp@intel.com> wrote:
> > >
> > > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> > > head:   ed5d0667a6540293c9485dd95babb5f1e241226a
> > > commit: 28dcfba1a0d622b0330ae3f4a9d7c7f2c245de7a [1932/6331] phy: ralink: Kconfig: enable COMPILE_TEST on mt7621-pci-phy driver
> > > config: x86_64-randconfig-r016-20210602 (attached as .config)
>
> ^ randconfig
>
> > > compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project db26cd30b6dd65e88d786e97a1e453af5cd48966)
> > > reproduce (this is a W=1 build):
> > >         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> > >         chmod +x ~/bin/make.cross
> > >         # install x86_64 cross compiling tool for clang build
> > >         # apt-get install binutils-x86-64-linux-gnu
> > >         # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=28dcfba1a0d622b0330ae3f4a9d7c7f2c245de7a
> > >         git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> > >         git fetch --no-tags linux-next master
> > >         git checkout 28dcfba1a0d622b0330ae3f4a9d7c7f2c245de7a
> > >         # save the attached .config to linux build tree
> > >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64
> > >
> > > If you fix the issue, kindly add following tag as appropriate
> > > Reported-by: kernel test robot <lkp@intel.com>
> > >
> > > All warnings (new ones prefixed by >>):
> > >
> > >    drivers/phy/ralink/phy-mt7621-pci.c:277:4: warning: cast to smaller integer type 'unsigned int' from 'void *' [-Wvoid-pointer-to-int-cast]
> > >                     (unsigned int)mt7621_phy->port_base, mt7621_phy->has_dual_port);
> > >                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > >    include/linux/dev_printk.h:118:33: note: expanded from macro 'dev_info'
> > >            _dev_info(dev, dev_fmt(fmt), ##__VA_ARGS__)
> >
> > Already fixed in:
> > https://git.kernel.org/pub/scm/linux/kernel/git/phy/linux-phy.git/commit/drivers/phy/ralink/phy-mt7621-pci.c?h=next&id=652a6a2e3824ce2ebf79a2d5326940d05c4db036
> >
> > >                                           ^~~~~~~~~~~
> > > >> drivers/phy/ralink/phy-mt7621-pci.c:341:34: warning: unused variable 'mt7621_pci_phy_ids' [-Wunused-const-variable]
> > >    static const struct of_device_id mt7621_pci_phy_ids[] = {
> > >                                     ^
> >
> > Mmmm... This one is used through MODULE_DEVICE_TABLE macro... Am I
> > missing something??
>
> Pretty sure there's a config in MODULE_DEVICE_TABLE that's being
> disabled by the randconfig; the definition of mt7621_pci_phy_ids
> should also be behind preprocessor checks for that.

So, the driver uses 'mt7621_pci_phy_ids' in two places :

static const struct of_device_id mt7621_pci_phy_ids[] = {
    { .compatible = "mediatek,mt7621-pci-phy" },
    {},
};
MODULE_DEVICE_TABLE(of, mt7621_pci_phy_ids);
^
This one is inside the 'MODULE' preprocessor directive.

static struct platform_driver mt7621_pci_phy_driver = {
    .probe = mt7621_pci_phy_probe,
    .driver = {
        .name = "mt7621-pci-phy",
        .of_match_table = of_match_ptr(mt7621_pci_phy_ids),
                                     ^
                                     This one is inside 'CONFIG_OF'
    },
};

randconfig is not setting 'CONFIG_OF' nor defining MODULE. I've been
looking into different drivers code and all of them follow the same
pattern and nothing is behind preprocessor checks at all. So I wonder
if this is really something that needs to be fixed.

Thanks in advance for clarifications.

Best regards,
    Sergio Paracuellos


>
> >
> > >    2 warnings generated.
> > >
> > >
> > > vim +/mt7621_pci_phy_ids +341 drivers/phy/ralink/phy-mt7621-pci.c
> > >
> > > d87da32372a03c Sergio Paracuellos 2020-11-21  340
> > > d87da32372a03c Sergio Paracuellos 2020-11-21 @341  static const struct of_device_id mt7621_pci_phy_ids[] = {
> > > d87da32372a03c Sergio Paracuellos 2020-11-21  342       { .compatible = "mediatek,mt7621-pci-phy" },
> > > d87da32372a03c Sergio Paracuellos 2020-11-21  343       {},
> > > d87da32372a03c Sergio Paracuellos 2020-11-21  344  };
> > > 8145dcb07d0c8b Sergio Paracuellos 2020-12-01  345  MODULE_DEVICE_TABLE(of, mt7621_pci_phy_ids);
> > > d87da32372a03c Sergio Paracuellos 2020-11-21  346
> > >
> > > :::::: The code at line 341 was first introduced by commit
> > > :::::: d87da32372a03ce121fc65ccd2c9a43edf56b364 phy: ralink: Add PHY driver for MT7621 PCIe PHY
> > >
> > > :::::: TO: Sergio Paracuellos <sergio.paracuellos@gmail.com>
> > > :::::: CC: Vinod Koul <vkoul@kernel.org>
> > >
> > > ---
> > > 0-DAY CI Kernel Test Service, Intel Corporation
> > > https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
> >
> > Best regards,
> >     Sergio Paracuellos
> >
> > --
> > You received this message because you are subscribed to the Google Groups "Clang Built Linux" group.
> > To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe@googlegroups.com.
> > To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/CAMhs-H8qyOKQmPtChYO%2BjfC%2BZmj8U9yGeZJORUx14MzyLeT5QA%40mail.gmail.com.
>
>
>
> --
> Thanks,
> ~Nick Desaulniers