Hi Tony,
[snip..]
>> > index dbf1e03..2bc51fb 100644
>> > --- a/arch/arm/plat-omap/counter_32k.c
>> > +++ b/arch/arm/plat-omap/counter_32k.c
>> > @@ -55,22 +55,29 @@ static u32 notrace omap_32k_read_sched_clock(void)
>> > * nsecs and adds to a monotonically increasing timespec.
>> > */
>> > static struct timespec persistent_ts;
>> > -static cycles_t cycles, last_cycles;
>> > +static cycles_t cycles;
>> > static unsigned int persistent_mult, persistent_shift;
>> > +static DEFINE_SPINLOCK(read_persistent_clock_lock);
>> > +
>> > static void omap_read_persistent_clock(struct timespec *ts)
>> > {
>> > unsigned long long nsecs;
>> > - cycles_t delta;
>> > - struct timespec *tsp = &persistent_ts;
>> > + cycles_t last_cycles;
>> > + unsigned long flags;
>> > +
>> > + spin_lock_irqsave(&read_persistent_clock_lock, flags);
>> >
>> > last_cycles = cycles;
>> > cycles = sync32k_cnt_reg ? __raw_readl(sync32k_cnt_reg) : 0;
>> > - delta = cycles - last_cycles;
>> >
>> > - nsecs = clocksource_cyc2ns(delta, persistent_mult, persistent_shift);
>> > + nsecs = clocksource_cyc2ns(cycles - last_cycles,
>> > + persistent_mult, persistent_shift);
>
> ..I think there's another bug here where cycles - last_cycles
> returns wrong value when the timer wraps around as cycles_t is
> 64 bits and the counter is 32 bits. It seems it's been there
> since when the read_persistent_clock was added with commit
> d92cfcbe (OMAP: timekeeping: time should not stop during suspend)?
>
> It seems that after this patch cycles should not be cycles_t
> but u32, and the result of cycles - last_cycles should also
> be u32.
>
cycles_t is defined as typedef unsigned long cycles_t;
Am i missing something here ?
Thanks,
Sricharan
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