Re: [PATCH 2/2] clocksource: sprd: Add timer driver for Spreadtrum SC9860 platform

[kbuild test robot <lkp@xxxxxxxxx>]

Hi Baolin,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on tip/timers/core]
[also build test WARNING on v4.14 next-20171124]
[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/Baolin-Wang/dt-bindings-clocksource-Add-Spreadtrum-SC9860-timer/20171125-090749
config: arm-allmodconfig (attached as .config)
compiler: arm-linux-gnueabi-gcc (Debian 7.2.0-11) 7.2.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=arm 

All warnings (new ones prefixed by >>):

   In file included from include/linux/swab.h:4:0,
                    from include/uapi/linux/byteorder/big_endian.h:12,
                    from include/linux/byteorder/big_endian.h:4,
                    from arch/arm/include/uapi/asm/byteorder.h:19,
                    from include/asm-generic/bitops/le.h:5,
                    from arch/arm/include/asm/bitops.h:340,
                    from include/linux/bitops.h:37,
                    from include/linux/kernel.h:10,
                    from include/linux/list.h:8,
                    from include/linux/preempt.h:10,
                    from include/linux/spinlock.h:50,
                    from include/linux/seqlock.h:35,
                    from include/linux/time.h:5,
                    from include/uapi/linux/timex.h:56,
                    from include/linux/timex.h:56,
                    from include/linux/clocksource.h:12,
                    from drivers/clocksource/sprd-timer.c:7:
   drivers/clocksource/sprd-timer.c: In function 'sprd_timer_update_counter':
   drivers/clocksource/sprd-timer.c:85:24: warning: right shift count >= width of type [-Wshift-count-overflow]
     writel_relaxed(cycles >> TIMER_VALUE_HI_SHIFT,
                           ^
   include/uapi/linux/swab.h:113:54: note: in definition of macro '__swab32'
    #define __swab32(x) (__u32)__builtin_bswap32((__u32)(x))
                                                         ^
   include/linux/byteorder/generic.h:87:21: note: in expansion of macro '__cpu_to_le32'
    #define cpu_to_le32 __cpu_to_le32
                        ^~~~~~~~~~~~~
>> drivers/clocksource/sprd-timer.c:85:2: note: in expansion of macro 'writel_relaxed'
     writel_relaxed(cycles >> TIMER_VALUE_HI_SHIFT,
     ^~~~~~~~~~~~~~

vim +/writel_relaxed +85 drivers/clocksource/sprd-timer.c

    79	
    80	static void sprd_timer_update_counter(struct sprd_timer_device *timer,
    81					      unsigned long cycles)
    82	{
    83		writel_relaxed(cycles & TIMER_VALUE_LO_MASK,
    84			       timer->base + TIMER_LOAD_LO);
  > 85		writel_relaxed(cycles >> TIMER_VALUE_HI_SHIFT,
    86			       timer->base + TIMER_LOAD_HI);
    87	}
    88	

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0-DAY kernel test infrastructure                Open Source Technology Center
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