Let's assume the counter value is 0xf000000, the pistachio clocksource read cycles function would return 0xffffffff0fffffff, but it should return 0xfffffff.
We fix this issue by calculating bitwise-not counter, then cast to cycle_t. Signed-off-by: Jisheng Zhang <[email protected]> --- drivers/clocksource/time-pistachio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/clocksource/time-pistachio.c b/drivers/clocksource/time-pistachio.c index bba6799..3269d9e 100644 --- a/drivers/clocksource/time-pistachio.c +++ b/drivers/clocksource/time-pistachio.c @@ -84,7 +84,7 @@ pistachio_clocksource_read_cycles(struct clocksource *cs) counter = gpt_readl(pcs->base, TIMER_CURRENT_VALUE, 0); raw_spin_unlock_irqrestore(&pcs->lock, flags); - return ~(cycle_t)counter; + return (cycle_t)~counter; } static u64 notrace pistachio_read_sched_clock(void) -- 2.6.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/

