Re: [spacemit:for-next 4/6] drivers/clk/spacemit/ccu-k1.c:241:1: error: initializer element is not a compile-time constant

[Alex Elder <elder@riscstar.com>]

On 4/15/25 8:44 AM, kernel test robot wrote:
> tree:   https://github.com/spacemit-com/linux for-next
> head:   9ead3efbc88a21e9a1f38948cc0902518022a2e5
> commit: e2d238ba301f25a5c8a7d490a36f9cd014d7aecc [4/6] clk: spacemit: Add clock support for SpacemiT K1 SoC
> config: s390-allmodconfig (https://download.01.org/0day-ci/archive/20250415/202504152107.7ekGPIrF-lkp@intel.com/config)
> compiler: clang version 18.1.8 (https://github.com/llvm/llvm-project 3b5b5c1ec4a3095ab096dd780e84d7ab81f3d7ff)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250415/202504152107.7ekGPIrF-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202504152107.7ekGPIrF-lkp@intel.com/
> 
> All errors (new ones prefixed by >>):

If I'm interpreting this right, this seems to be a problem on
a S390 build (under COMPILE_TEST), because there is no constant
version of the __ffs() for that architecture.  This might be the
case on other architectures as well.

On RISC-V, this is fine.

Any recommendations on how to address this?

					-Alex



> 
>>> drivers/clk/spacemit/ccu-k1.c:241:1: error: initializer element is not a compile-time constant
>       241 | CCU_DDN_DEFINE(slow_uart1_14p74, pll1_d16_153p6, MPMU_SUCCR, GENMASK(28, 16), GENMASK(12, 0), 0);
>           | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>     drivers/clk/spacemit/ccu_ddn.h:33:15: note: expanded from macro 'CCU_DDN_DEFINE'
>        33 |         .num_shift      = __ffs(_num_mask),                                     \
>           |                           ^~~~~~~~~~~~~~~~
>     drivers/clk/spacemit/ccu-k1.c:242:1: error: initializer element is not a compile-time constant
>       242 | CCU_DDN_DEFINE(slow_uart2_48, pll1_d4_614p4, MPMU_SUCCR_1, GENMASK(28, 16), GENMASK(12, 0), 0);
>           | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>     drivers/clk/spacemit/ccu_ddn.h:33:15: note: expanded from macro 'CCU_DDN_DEFINE'
>        33 |         .num_shift      = __ffs(_num_mask),                                     \
>           |                           ^~~~~~~~~~~~~~~~
>     2 errors generated.
> 
> 
> vim +241 drivers/clk/spacemit/ccu-k1.c
> 
>     239	
>     240	CCU_GATE_DEFINE(slow_uart, CCU_PARENT_NAME(osc), MPMU_ACGR, BIT(1), CLK_IGNORE_UNUSED);
>   > 241	CCU_DDN_DEFINE(slow_uart1_14p74, pll1_d16_153p6, MPMU_SUCCR, GENMASK(28, 16), GENMASK(12, 0), 0);
>     242	CCU_DDN_DEFINE(slow_uart2_48, pll1_d4_614p4, MPMU_SUCCR_1, GENMASK(28, 16), GENMASK(12, 0), 0);
>     243	
>