Hi Michael,

I love your patch! Perhaps something to improve:

[auto build test WARNING on usb/usb-testing]
[also build test WARNING on peter-chen-usb/for-usb-next v5.16-rc1 next-20211116]
[cannot apply to media-tree/master balbi-usb/testing/next]
[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]

url:    https://github.com/0day-ci/linux/commits/Michael-Grzeschik/usb-gadget-uvc-use-configfs-entries-for-negotiation-and-v4l2-VIDIOCS/20211117-084501
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
config: nds32-buildonly-randconfig-r005-20211116 (attached as .config)
compiler: nds32le-linux-gcc (GCC) 11.2.0
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
        # https://github.com/0day-ci/linux/commit/3227638d6b37451cc22e7ee61a3311ec3f6498ce
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Michael-Grzeschik/usb-gadget-uvc-use-configfs-entries-for-negotiation-and-v4l2-VIDIOCS/20211117-084501
        git checkout 3227638d6b37451cc22e7ee61a3311ec3f6498ce
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=nds32 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <redacted>

All warnings (new ones prefixed by >>):

quoted

drivers/usb/gadget/function/uvc_v4l2.c:52:5: warning: no previous prototype for 'uvc_v4l2_get_bytesperline' [-Wmissing-prototypes]

      52 | int uvc_v4l2_get_bytesperline(struct uvcg_format *uformat,
         |     ^~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/usb/gadget/function/uvc_v4l2.c: In function '_uvc_v4l2_try_fmt':
   drivers/usb/gadget/function/uvc_v4l2.c:240:13: warning: unused variable 'i' [-Wunused-variable]
     240 |         int i = 0;
         |             ^
   In file included from drivers/usb/gadget/function/uvc_v4l2.c:29:
   At top level:
   drivers/usb/gadget/function/uvc_configfs.h:40:27: warning: 'uvcg_format_names' defined but not used [-Wunused-const-variable=]
      40 | static const char * const uvcg_format_names[] = {
         |                           ^~~~~~~~~~~~~~~~~


vim +/uvc_v4l2_get_bytesperline +52 drivers/usb/gadget/function/uvc_v4l2.c

    51	
  > 52	int uvc_v4l2_get_bytesperline(struct uvcg_format *uformat,
    53				      struct uvcg_frame *uframe)
    54	{
    55		struct uvcg_uncompressed *u;
    56	
    57		if (uformat->type == UVCG_UNCOMPRESSED) {
    58			u = to_uvcg_uncompressed(&uformat->group.cg_item);
    59			if (!u)
    60				return 0;
    61	
    62			return u->desc.bBitsPerPixel * uframe->frame.w_width / 8;
    63		}
    64	
    65		return 0;
    66	}
    67	

---
0-DAY CI Kernel Test Service, Intel Corporation
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