Re: [PATCH v5 1/2] iommu - Enable debugfs exposure of IOMMU driver internals

[Hook, Gary]

On 5/7/2018 6:47 PM, kbuild test robot wrote:
Hi Gary,

I imagine these questions have been asked before, so I'll ask for
forgiveness up front.


Thank you for the patch! Yet something to improve:

[auto build test ERROR on iommu/next]
[also build test ERROR on v4.17-rc4 next-20180507]
[if your patch is applied to the wrong git tree, please drop us a note to help 
improve the system]

url:    
https://github.com/0day-ci/linux/commits/Gary-R-Hook/iommu-Enable-debugfs-exposure-of-IOMMU-driver-internals/20180508-062918
base:   https://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git next
config: x86_64-randconfig-x016-201818 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-16) 7.3.0
reproduce:
         # save the attached .config to linux build tree
         make ARCH=x86_64

Is the gcc 7 compiler now a requirement to build the kernel? Or only to 
run krobot tests?

Is this the earliest version of the compiler that can be used? I'm still 
using 4.8 and 5.4, which seems to suffice for the kernel.

Googling about this has been fruitless.


All error/warnings (new ones prefixed by >>):

    In file included from include/linux/intel-iommu.h:32:0,
                     from drivers/gpu/drm/i915/i915_drv.h:41,
                     from drivers/gpu/drm/i915/i915_oa_bxt.c:31:
    include/linux/iommu.h: In function 'iommu_debugfs_new_driver_dir':
include/linux/iommu.h:706:8: error: parameter name omitted
     struct dentry *iommu_debugfs_new_driver_dir(char *) {};
            ^~~~~~
    In file included from include/linux/intel-iommu.h:32:0,
                     from drivers/gpu/drm/i915/i915_drv.h:41,
                     from drivers/gpu/drm/i915/i915_oa_bxt.c:31:
include/linux/iommu.h:706:8: warning: control reaches end of non-void function 
[-Wreturn-type]
     struct dentry *iommu_debugfs_new_driver_dir(char *) {};
            ^~~~~~

vim +706 include/linux/iommu.h

    700 
    701 #ifdef CONFIG_IOMMU_DEBUGFS
    702 void iommu_debugfs_setup(void);
    703 struct dentry *iommu_debugfs_new_driver_dir(char *);
    704 #else
    705 static inline void iommu_debugfs_setup(void) {}
  > 706      struct dentry *iommu_debugfs_new_driver_dir(char *) {};
    707 #endif
    708 

I have no problems with adding parameter names. But 
scripts/checkpatch.pl doesn't seem to check for this, nor require it. 
Should checkpatch be updated?