On Wed, 19 May 2010, David Daney wrote:
> The 'mult' element of struct clock_event_device must never be wider
> than 32-bits. If it were, it would get truncated when used by
> clockevent_delta2ns() when this calls do_div().
>
> We can meet this requirement by using clockevent_set_clock() to set
> the MULT and SHIFT values.
>
> Signed-off-by: David Daney <ddaney@xxxxxxxxxxxxxxxxxx>
> CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> ---
> arch/mips/kernel/cevt-r4k.c | 5 ++---
> 1 files changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/arch/mips/kernel/cevt-r4k.c b/arch/mips/kernel/cevt-r4k.c
> index 0b2450c..2a4d50f 100644
> --- a/arch/mips/kernel/cevt-r4k.c
> +++ b/arch/mips/kernel/cevt-r4k.c
> @@ -163,7 +163,6 @@ int c0_compare_int_usable(void)
>
> int __cpuinit r4k_clockevent_init(void)
> {
> - uint64_t mips_freq = mips_hpt_frequency;
> unsigned int cpu = smp_processor_id();
> struct clock_event_device *cd;
> unsigned int irq;
> @@ -188,9 +187,9 @@ int __cpuinit r4k_clockevent_init(void)
> cd->name = "MIPS";
> cd->features = CLOCK_EVT_FEAT_ONESHOT;
>
> + clockevent_set_clock(cd, mips_hpt_frequency);
> +
> /* Calculate the min / max delta */
> - cd->mult = div_sc((unsigned long) mips_freq, NSEC_PER_SEC, 32);
> - cd->shift = 32;
> cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
> cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
>
> --
> 1.6.6.1
>
