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From:   Sergio Paracuellos <sergio.paracuellos@gmail.com>
Date:   Thu, 26 May 2022 07:24:04 +0200
Message-ID: <CAMhs-H_5kHmvG5F=KZaDMzQ8VbSQfg_qqVnzCMuntpH9YU+V4Q@mail.gmail.com>
Subject: Re: [PATCH] MIPS: RALINK: Define pci_remap_iospace under CONFIG_PCI_DRIVERS_GENERIC
To:     Tiezhu Yang <yangtiezhu@loongson.cn>
Cc:     Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        Xuefeng Li <lixuefeng@loongson.cn>,
        "open list:MIPS" <linux-mips@vger.kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        kernel test robot <lkp@intel.com>
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On Wed, May 25, 2022 at 8:59 PM Tiezhu Yang <yangtiezhu@loongson.cn> wrote:
>
> kernel test robot reports a build error used with clang compiler and
> mips-randconfig [1]:
>
>     ld.lld: error: undefined symbol: pci_remap_iospace
>
> we can see the following configs in the mips-randconfig file:
>
>     CONFIG_RALINK=y
>     CONFIG_SOC_MT7620=y
>     CONFIG_PCI_DRIVERS_LEGACY=y
>     CONFIG_PCI=y
>
> CONFIG_RALINK is set, so pci_remap_iospace is defined in the related
> arch/mips/include/asm/mach-ralink/spaces.h header file:
>
>     #define pci_remap_iospace pci_remap_iospace
>
> CONFIG_PCI is set, so pci_remap_iospace() in drivers/pci/pci.c is not
> built due to pci_remap_iospace is defined under CONFIG_RALINK.
>
>     #ifndef pci_remap_iospace
>     int pci_remap_iospace(const struct resource *res, ...)
>
>     $ objdump -d drivers/pci/pci.o | grep pci_remap_iospace
>     00004cc8 <devm_pci_remap_iospace>:
>         4d18:   10400008        beqz    v0,4d3c <devm_pci_remap_iospace+0x74>
>         4d2c:   1040000c        beqz    v0,4d60 <devm_pci_remap_iospace+0x98>
>         4d70:   1000fff3        b       4d40 <devm_pci_remap_iospace+0x78>
>
> In addition, CONFIG_PCI_DRIVERS_GENERIC is not set, so pci_remap_iospace()
> in arch/mips/pci/pci-generic.c is not built too.
>
>     #ifdef pci_remap_iospace
>     int pci_remap_iospace(const struct resource *res, ...)
>
> For the above reasons, undefined reference pci_remap_iospace() looks like
> reasonable.
>
> Here are simple steps to reproduce used with gcc and defconfig:
>
>     cd mips.git
>     make vocore2_defconfig # set RALINK, SOC_MT7620, PCI_DRIVERS_LEGACY
>     make menuconfig        # set PCI
>     make
>
> there exists the following build error:
>
>       LD      vmlinux.o
>       MODPOST vmlinux.symvers
>       MODINFO modules.builtin.modinfo
>       GEN     modules.builtin
>       LD      .tmp_vmlinux.kallsyms1
>     drivers/pci/pci.o: In function `devm_pci_remap_iospace':
>     pci.c:(.text+0x4d24): undefined reference to `pci_remap_iospace'
>     Makefile:1158: recipe for target 'vmlinux' failed
>     make: *** [vmlinux] Error 1
>
> Define pci_remap_iospace under CONFIG_PCI_DRIVERS_GENERIC can fix the build
> error, with this patch, no build error remains. This patch is similar with
> commit e538e8649892 ("MIPS: asm: pci: define arch-specific
> 'pci_remap_iospace()' dependent on 'CONFIG_PCI_DRIVERS_GENERIC'").
>
> [1] https://lore.kernel.org/lkml/202205251247.nQ5cxSV6-lkp@intel.com/
>
> Fixes: 09d97da660ff ("MIPS: Only define pci_remap_iospace() for Ralink")
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
> ---
>  arch/mips/include/asm/mach-ralink/spaces.h | 2 ++
>  1 file changed, 2 insertions(+)

Acked-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>