Re: [PATCH V3 1/3] iommu/arm-smmu-v3: Add device-tree support for CMDQV driver

[Ashish Mhetre]

On 12/3/2025 9:19 PM, Robin Murphy wrote:
> External email: Use caution opening links or attachments
>
>
> On 2025-12-03 11:04 am, Ashish Mhetre wrote:
> > On 12/3/2025 2:05 PM, kernel test robot wrote:
> > > External email: Use caution opening links or attachments
> > >
> > >
> > > Hi Ashish,
> > >
> > > kernel test robot noticed the following build errors:
> > >
> > > [auto build test ERROR on next-20251201]
> > > [also build test ERROR on v6.18]
> > > [cannot apply to robh/for-next linus/master v6.18 v6.18-rc7 v6.18-rc6]
> > > [If your patch is applied to the wrong git tree, kindly drop us a note.
> > > And when submitting patch, we suggest to use '--base' as documented in
> > > https://git-scm.com/docs/git-format-patch#_base_tree_information]
> > >
> > > url: https://github.com/intel-lab-lkp/linux/commits/Ashish-Mhetre/
> > > iommu-arm-smmu-v3-Add-device-tree-support-for-CMDQV-
> > > driver/20251202-003517
> > > base:   next-20251201
> > > patch link: https://lore.kernel.org/r/20251201163219.3237266-2-
> > > amhetre%40nvidia.com
> > > patch subject: [PATCH V3 1/3] iommu/arm-smmu-v3: Add device-tree
> > > support for CMDQV driver
> > > config: arm64-allmodconfig (https://download.01.org/0day-ci/
> > > archive/20251203/202512031601.IpliwbHW-lkp@xxxxxxxxx/config)
> > > compiler: clang version 19.1.7 (https://github.com/llvm/llvm-project
> > > cd708029e0b2869e80abe31ddb175f7c35361f90)
> > > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/
> > > archive/20251203/202512031601.IpliwbHW-lkp@xxxxxxxxx/reproduce)
> > >
> > > If you fix the issue in a separate patch/commit (i.e. not just a new
> > > version of
> > > the same patch/commit), kindly add following tags
> > > | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > > | Closes: https://lore.kernel.org/oe-kbuild-all/202512031601.IpliwbHW-
> > > lkp@xxxxxxxxx/
> > >
> > > All errors (new ones prefixed by >>):
> > >
> > > > > ld.lld: error: duplicate symbol: init_module
> > >     >>> defined at arm-smmu-v3.c
> > >     >>> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.o:
> > > (init_module)
> > >     >>> defined at tegra241-cmdqv.c
> > >     >>> drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.o:
> > > (.init.text+0x4)
> > > --
> > > > > ld.lld: error: duplicate symbol: cleanup_module
> > >     >>> defined at arm-smmu-v3.c
> > >     >>> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.o:
> > > (cleanup_module)
> > >     >>> defined at tegra241-cmdqv.c
> > >     >>> drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.o:
> > > (.exit.text+0x4)
> >
> > Hi Nic, Robin,
> >
> > How do you suggest fixing this? Is it fine to compile tegra241-cmdqv as
> > separate module
> > and export tegra241_cmdqv_probe() to fix this warning?
>
> As Jon just pointed out, the issue is using module_platform_driver(),
> which is unnecessary anyway since this is not a driver; nor is it even a
> module, it's just some extra code that can be included in the
> arm_smmu_v3 driver, and will be integral to the arm_smmu_v3.ko module if
> built as a such.
>
> You could sanity-check the compatible of the phandle target in
> tegra_cmdqv_dt_probe() if you feel like you should do more than just
> blindly trust the DT, but either way trying to register a dummy platform
> driver that won't bind to anything is pointless.

Thanks for the pointers Jon, Robin. I agree that this part of code is
redundant and can be removed. I will make these changes in next version.

> > I am using GCC compiler and was not able to reproduce this with W=1 
> > build.
>
> This will be happening with CONFIG_ARM_SMMU_V3=m.
>
> Thanks,
> Robin.
>
> > Thanks,
> > Ashish Mhetre
> >
> > > --
> > > 0-DAY CI Kernel Test Service
> > > https://github.com/intel/lkp-tests/wiki