[tip:timers/urgent 1/1] include/linux/jiffies.h:470:36: sparse: sparse: cast truncates bits from constant value (3fffffffffff85ee becomes ffff85ee)

From: kernel test robot

Date: Wed Feb 11 2026 - 19:30:12 EST


tree: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers/urgent
head: b777b5e09eabeefc6ba80f4296366a4742701103
commit: b777b5e09eabeefc6ba80f4296366a4742701103 [1/1] time/jiffies: Inline jiffies_to_msecs() and jiffies_to_usecs()
config: alpha-randconfig-r133-20260212 (https://download.01.org/0day-ci/archive/20260212/202602120804.UOTwdKQt-lkp@xxxxxxxxx/config)
compiler: alpha-linux-gcc (GCC) 8.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260212/202602120804.UOTwdKQt-lkp@xxxxxxxxx/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@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202602120804.UOTwdKQt-lkp@xxxxxxxxx/

sparse warnings: (new ones prefixed by >>)
drivers/gpio/gpiolib-cdev.c: note: in included file (through include/linux/ktime.h, include/linux/timer.h, include/linux/uprobes.h, ...):
>> include/linux/jiffies.h:470:36: sparse: sparse: cast truncates bits from constant value (3fffffffffff85ee becomes ffff85ee)
>> include/linux/jiffies.h:470:36: sparse: sparse: cast truncates bits from constant value (3fffffffffff85ee becomes ffff85ee)

vim +470 include/linux/jiffies.h

454
455 #if !(USEC_PER_SEC % HZ)
456 /**
457 * jiffies_to_usecs - Convert jiffies to microseconds
458 * @j: jiffies value
459 *
460 * Return: microseconds value
461 */
462 static inline unsigned int jiffies_to_usecs(const unsigned long j)
463 {
464 /*
465 * Hz usually doesn't go much further MSEC_PER_SEC.
466 * jiffies_to_usecs() and usecs_to_jiffies() depend on that.
467 */
468 BUILD_BUG_ON(HZ > USEC_PER_SEC);
469
> 470 return (USEC_PER_SEC / HZ) * j;
471 }
472 #else
473 unsigned int jiffies_to_usecs(const unsigned long j);
474 #endif
475

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