Re: [PATCH] i2c: pasemi: Add IRQ support for Apple Silicon

[kernel test robot <lkp@intel.com>]

Hi Arminder,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on powerpc/next]
[also build test WARNING on linus/master v6.0-rc1 next-20220819]
[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/Arminder-Singh/i2c-pasemi-Add-IRQ-support-for-Apple-Silicon/20220821-034703
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: riscv-randconfig-r042-20220821 (https://download.01.org/0day-ci/archive/20220821/202208210548.MCoIwyQl-lkp@intel.com/config)
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project c9a41fe60ab62f7a40049c100adcc8087a47669b)
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 riscv cross compiling tool for clang build
        # apt-get install binutils-riscv64-linux-gnu
        # https://github.com/intel-lab-lkp/linux/commit/98584b2b51d808ab582798c7a50511e8c1889ced
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Arminder-Singh/i2c-pasemi-Add-IRQ-support-for-Apple-Silicon/20220821-034703
        git checkout 98584b2b51d808ab582798c7a50511e8c1889ced
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash drivers/i2c/busses/

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   In file included from drivers/i2c/busses/i2c-pasemi-core.c:9:
   In file included from include/linux/pci.h:38:
   In file included from include/linux/interrupt.h:11:
   In file included from include/linux/hardirq.h:11:
   In file included from ./arch/riscv/include/generated/asm/hardirq.h:1:
   In file included from include/asm-generic/hardirq.h:17:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:136:
   include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           val = __raw_readb(PCI_IOBASE + addr);
                             ~~~~~~~~~~ ^
   include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
                                                           ~~~~~~~~~~ ^
   include/uapi/linux/byteorder/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu'
   #define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
                                                     ^
   In file included from drivers/i2c/busses/i2c-pasemi-core.c:9:
   In file included from include/linux/pci.h:38:
   In file included from include/linux/interrupt.h:11:
   In file included from include/linux/hardirq.h:11:
   In file included from ./arch/riscv/include/generated/asm/hardirq.h:1:
   In file included from include/asm-generic/hardirq.h:17:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:136:
   include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
                                                           ~~~~~~~~~~ ^
   include/uapi/linux/byteorder/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu'
   #define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
                                                     ^
   In file included from drivers/i2c/busses/i2c-pasemi-core.c:9:
   In file included from include/linux/pci.h:38:
   In file included from include/linux/interrupt.h:11:
   In file included from include/linux/hardirq.h:11:
   In file included from ./arch/riscv/include/generated/asm/hardirq.h:1:
   In file included from include/asm-generic/hardirq.h:17:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:13:
   In file included from arch/riscv/include/asm/io.h:136:
   include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           __raw_writeb(value, PCI_IOBASE + addr);
                               ~~~~~~~~~~ ^
   include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
                                                         ~~~~~~~~~~ ^
   include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
                                                         ~~~~~~~~~~ ^
   include/asm-generic/io.h:1134:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
           return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port;
                                                     ~~~~~~~~~~ ^
>> drivers/i2c/busses/i2c-pasemi-core.c:86:6: warning: variable 'status' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
           if (smbus->use_irq) {
               ^~~~~~~~~~~~~~
   drivers/i2c/busses/i2c-pasemi-core.c:92:12: note: uninitialized use occurs here
                   while (!(status & SMSTA_XEN) && timeout--) {
                            ^~~~~~
   drivers/i2c/busses/i2c-pasemi-core.c:86:2: note: remove the 'if' if its condition is always true
           if (smbus->use_irq) {
           ^~~~~~~~~~~~~~~~~~~~
   drivers/i2c/busses/i2c-pasemi-core.c:83:21: note: initialize the variable 'status' to silence this warning
           unsigned int status;
                              ^
                               = 0
   8 warnings generated.


vim +86 drivers/i2c/busses/i2c-pasemi-core.c

    79	
    80	static int pasemi_smb_waitready(struct pasemi_smbus *smbus)
    81	{
    82		int timeout = 10;
    83		unsigned int status;
    84		unsigned int bitmask = SMSTA_XEN | SMSTA_MTN;
    85	
  > 86		if (smbus->use_irq) {
    87			reinit_completion(&smbus->irq_completion);
    88			reg_write(smbus, REG_IMASK, bitmask);
    89			wait_for_completion_timeout(&smbus->irq_completion, msecs_to_jiffies(10));
    90			status = reg_read(smbus, REG_SMSTA);
    91		} else {
    92			while (!(status & SMSTA_XEN) && timeout--) {
    93				msleep(1);
    94				status = reg_read(smbus, REG_SMSTA);
    95			}
    96		}
    97	
    98	
    99		/* Got NACK? */
   100		if (status & SMSTA_MTN)
   101			return -ENXIO;
   102	
   103		if (timeout < 0) {
   104			dev_warn(smbus->dev, "Timeout, status 0x%08x\n", status);
   105			reg_write(smbus, REG_SMSTA, status);
   106			return -ETIME;
   107		}
   108	
   109		/* Clear XEN */
   110		reg_write(smbus, REG_SMSTA, SMSTA_XEN);
   111	
   112		return 0;
   113	}
   114	

-- 
0-DAY CI Kernel Test Service
https://01.org/lkp