Hi Diana,

FYI, the error/warning still remains.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   b7cbaf59f62f8ab8f157698f9e31642bff525bd0
commit: cc0ee20bd96971c10eba9a83ecf1c0733078a083 vfio/fsl-mc: trigger an interrupt via eventfd
date:   3 weeks ago
config: arm64-randconfig-r026-20201101 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 235dfcf70abca65dba5d80f1a42d1485bab8980c)
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 arm64 cross compiling tool for clang build
        # apt-get install binutils-aarch64-linux-gnu
        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cc0ee20bd96971c10eba9a83ecf1c0733078a083
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout cc0ee20bd96971c10eba9a83ecf1c0733078a083
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64 

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/vfio/fsl-mc/vfio_fsl_mc_intr.c:16:5: warning: no previous prototype for function 'vfio_fsl_mc_irqs_allocate' [-Wmissing-prototypes]
   int vfio_fsl_mc_irqs_allocate(struct vfio_fsl_mc_device *vdev)
       ^
   drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c:16:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   int vfio_fsl_mc_irqs_allocate(struct vfio_fsl_mc_device *vdev)
   ^
   static 
   drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c:121:8: error: implicit declaration of function 'fsl_mc_populate_irq_pool' [-Werror,-Wimplicit-function-declaration]
           ret = fsl_mc_populate_irq_pool(mc_cont,
                 ^
   drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c:122:4: error: use of undeclared identifier 'FSL_MC_IRQ_POOL_MAX_TOTAL_IRQS'
                           FSL_MC_IRQ_POOL_MAX_TOTAL_IRQS);
                           ^
   1 warning and 2 errors generated.

vim +/vfio_fsl_mc_irqs_allocate +16 drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c

    15	
  > 16	int vfio_fsl_mc_irqs_allocate(struct vfio_fsl_mc_device *vdev)
    17	{
    18		struct fsl_mc_device *mc_dev = vdev->mc_dev;
    19		struct vfio_fsl_mc_irq *mc_irq;
    20		int irq_count;
    21		int ret, i;
    22	
    23		/* Device does not support any interrupt */
    24		if (mc_dev->obj_desc.irq_count == 0)
    25			return 0;
    26	
    27		/* interrupts were already allocated for this device */
    28		if (vdev->mc_irqs)
    29			return 0;
    30	
    31		irq_count = mc_dev->obj_desc.irq_count;
    32	
    33		mc_irq = kcalloc(irq_count, sizeof(*mc_irq), GFP_KERNEL);
    34		if (!mc_irq)
    35			return -ENOMEM;
    36	
    37		/* Allocate IRQs */
    38		ret = fsl_mc_allocate_irqs(mc_dev);
    39		if (ret) {
    40			kfree(mc_irq);
    41			return ret;
    42		}
    43	
    44		for (i = 0; i < irq_count; i++) {
    45			mc_irq[i].count = 1;
    46			mc_irq[i].flags = VFIO_IRQ_INFO_EVENTFD;
    47		}
    48	
    49		vdev->mc_irqs = mc_irq;
    50	
    51		return 0;
    52	}
    53	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org