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| author | Paul Mackerras <paulus@samba.org> | 2008-09-10 11:36:13 +1000 |
|---|---|---|
| committer | Paul Mackerras <paulus@samba.org> | 2008-09-10 11:36:13 +1000 |
| commit | 7e392f8c29ee045c6a29d50193d2fb10712eceb0 (patch) | |
| tree | c84097fe644c50c82f087ab7fa2d75167b8c0e16 /arch/x86/kernel/hpet.c | |
| parent | 7713fef06517d216f96ee7c8ad750e72bc08d38f (diff) | |
| parent | 93811d94f7e9bcfeed7d6ba75ea5d9c80a70ab95 (diff) | |
| download | linux-7e392f8c29ee045c6a29d50193d2fb10712eceb0.tar.gz linux-7e392f8c29ee045c6a29d50193d2fb10712eceb0.tar.bz2 linux-7e392f8c29ee045c6a29d50193d2fb10712eceb0.zip | |
Merge branch 'linux-2.6'
Diffstat (limited to 'arch/x86/kernel/hpet.c')
| -rw-r--r-- | arch/x86/kernel/hpet.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c index 59fd3b6b1303..73deaffadd03 100644 --- a/arch/x86/kernel/hpet.c +++ b/arch/x86/kernel/hpet.c @@ -210,8 +210,8 @@ static void hpet_legacy_clockevent_register(void) /* Calculate the min / max delta */ hpet_clockevent.max_delta_ns = clockevent_delta2ns(0x7FFFFFFF, &hpet_clockevent); - hpet_clockevent.min_delta_ns = clockevent_delta2ns(0x30, - &hpet_clockevent); + /* 5 usec minimum reprogramming delta. */ + hpet_clockevent.min_delta_ns = 5000; /* * Start hpet with the boot cpu mask and make it @@ -270,15 +270,22 @@ static void hpet_legacy_set_mode(enum clock_event_mode mode, } static int hpet_legacy_next_event(unsigned long delta, - struct clock_event_device *evt) + struct clock_event_device *evt) { - unsigned long cnt; + u32 cnt; cnt = hpet_readl(HPET_COUNTER); - cnt += delta; + cnt += (u32) delta; hpet_writel(cnt, HPET_T0_CMP); - return ((long)(hpet_readl(HPET_COUNTER) - cnt ) > 0) ? -ETIME : 0; + /* + * We need to read back the CMP register to make sure that + * what we wrote hit the chip before we compare it to the + * counter. + */ + WARN_ON((u32)hpet_readl(HPET_T0_CMP) != cnt); + + return (s32)((u32)hpet_readl(HPET_COUNTER) - cnt) >= 0 ? -ETIME : 0; } /* |