Hello.
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 meet the requirement by ensuring that the relationship:
(mips_hpt_frequency >> (32 - shift)) < NSEC_PER_SEC
Always holds.
Signed-off-by: David Daney <ddaney@xxxxxxxxxxxxxxxxxx>
CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
[...]
diff --git a/arch/mips/kernel/cevt-r4k.c b/arch/mips/kernel/cevt-r4k.c
index 0b2450c..4495158 100644
--- a/arch/mips/kernel/cevt-r4k.c
+++ b/arch/mips/kernel/cevt-r4k.c
[...]
@@ -189,8 +190,17 @@ int __cpuinit r4k_clockevent_init(void)
cd->features = CLOCK_EVT_FEAT_ONESHOT;
/* Calculate the min / max delta */
- cd->mult = div_sc((unsigned long) mips_freq, NSEC_PER_SEC, 32);
- cd->shift = 32;
+ shift = 32;
+ while (scaled_freq >= NSEC_PER_SEC && shift) {
+ scaled_freq = scaled_freq >> 1;
Why not:
scaled_freq >>= 1;
It's C after all. :-)
WBR, Sergei
