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| author | Jesper Nilsson <jesper.nilsson@axis.com> | 2010-07-30 17:33:07 +0200 |
|---|---|---|
| committer | Jesper Nilsson <jesper.nilsson@axis.com> | 2010-08-04 12:58:55 +0200 |
| commit | 60dbd6633178a8625ed71329da0167c6d50c559c (patch) | |
| tree | bcbc1004dfe356ce7cf30f183725dbbc9dad3e4f /arch/cris/kernel | |
| parent | 26bfeea38a4a5daf52c8f01c986ca8680bf1f6a1 (diff) | |
| download | linux-60dbd6633178a8625ed71329da0167c6d50c559c.tar.bz2 | |
CRIS: GENERIC_TIME fixes
GENERIC_TIME was not functional for CRIS, giving random backward
time jumps.
For CRISv32 implement a new clocksource using the free running counter
and ditch the arch_gettimeoffset.
The random time jumps still existed, but turned out to be the write_seqlock
which was missing around our do_timer() call.
So switch over to GENERIC_TIME using the clocksource for CRISv32.
CRISv10 doesn't have the free running counter needed for the
clocksource trick, but we can still use GENERIC_TIME with
arch_gettimeoffset.
Unfortunately, there were problems in using the prescaler register
to timer0 for the gettimeoffset calculation, so it is now ignored,
making our resolution worse by the tune of 40usec (0.4%) worst case.
At the same time, clean up some formatting and use NSEC_PER_SEC
instead of 1000000000.
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Diffstat (limited to 'arch/cris/kernel')
| -rw-r--r-- | arch/cris/kernel/time.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/cris/kernel/time.c b/arch/cris/kernel/time.c index c72730d20ef6..b5096430ce1c 100644 --- a/arch/cris/kernel/time.c +++ b/arch/cris/kernel/time.c @@ -39,13 +39,16 @@ int have_rtc; /* used to remember if we have an RTC or not */; extern unsigned long loops_per_jiffy; /* init/main.c */ unsigned long loops_per_usec; + +#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET extern unsigned long do_slow_gettimeoffset(void); static unsigned long (*do_gettimeoffset)(void) = do_slow_gettimeoffset; u32 arch_gettimeoffset(void) { - return do_gettimeoffset() * 1000; + return do_gettimeoffset() * 1000; } +#endif /* * BUG: This routine does not handle hour overflow properly; it just @@ -151,7 +154,7 @@ cris_do_profile(struct pt_regs* regs) unsigned long long sched_clock(void) { - return (unsigned long long)jiffies * (1000000000 / HZ) + + return (unsigned long long)jiffies * (NSEC_PER_SEC / HZ) + get_ns_in_jiffie(); } |