Re: [PATCH v6] x86/hpet: Reduce HPET counter read contention

[Waiman Long <waiman.long@hpe.com>]

On 08/12/2016 10:30 PM, kbuild test robot wrote:
> Hi Waiman,
>
> [auto build test ERROR on tip/auto-latest]
> [also build test ERROR on v4.8-rc1 next-20160812]
> [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/Waiman-Long/x86-hpet-Reduce-HPET-counter-read-contention/20160813-090247
> config: x86_64-randconfig-s0-08131002 (attached as .config)
> compiler: gcc-4.4 (Debian 4.4.7-8) 4.4.7
> reproduce:
>          # save the attached .config to linux build tree
>          make ARCH=x86_64
>
> All error/warnings (new ones prefixed by>>):
>
>>> arch/x86/kernel/hpet.c:791: error: unknown field 'lock' specified in initializer
>>> arch/x86/kernel/hpet.c:791: warning: missing braces around initializer
>     arch/x86/kernel/hpet.c:791: warning: (near initialization for 'hpet.<anonymous>.lock.val')
>
> vim +/lock +791 arch/x86/kernel/hpet.c
>
>     785			u32 value;
>     786		};
>     787		u64 lockval;
>     788	};
>     789	
>     790	static union hpet_lock hpet __cacheline_aligned = {
>   >  791		.lock = __ARCH_SPIN_LOCK_UNLOCKED,
>     792	};
>     793	
>     794	static cycle_t read_hpet(struct clocksource *cs)
>
> ---
> 0-DAY kernel test infrastructure                Open Source Technology Center
> https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

The following additional patch should fix the build error. The error 
wasn't produced when I did my test build with the gcc 4.8.5 compiler. 
That was why I missed it.

Cheers,
Longman

----------------------------------

diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 71127fe..0822688 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -788,7 +788,7 @@ union hpet_lock {
  };

  static union hpet_lock hpet __cacheline_aligned = {
-       .lock = __ARCH_SPIN_LOCK_UNLOCKED,
+       { .lock = __ARCH_SPIN_LOCK_UNLOCKED, },
  };

  static cycle_t read_hpet(struct clocksource *cs)