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| author | David Daney <ddaney@caviumnetworks.com> | 2010-05-19 10:40:53 -0700 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2010-08-05 13:25:39 +0100 |
| commit | 4d2b11252b92c6aca9f9222ee05e00f7262c2e53 (patch) | |
| tree | 7d9f51b5ecc324c6ea45f55105a4e1b74f3c7b70 | |
| parent | 6165df980801e1be7a5b65686bd52f55e0407db1 (diff) | |
| download | kernel_samsung_smdk4412-4d2b11252b92c6aca9f9222ee05e00f7262c2e53.zip kernel_samsung_smdk4412-4d2b11252b92c6aca9f9222ee05e00f7262c2e53.tar.gz kernel_samsung_smdk4412-4d2b11252b92c6aca9f9222ee05e00f7262c2e53.tar.bz2 | |
MIPS: Don't overflow cevt-r4k.c calculations at high clock rates.
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@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1253/
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| -rw-r--r-- | 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); |