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author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-03-15 20:01:36 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-03-15 20:01:36 -0700 |
commit | d10902812c9cd5583130a4ebb9ad19c60b68149d (patch) | |
tree | b1b28587970e8cebf74ba4d61edf49537f619ab7 /arch/x86/kernel/apb_timer.c | |
parent | 181f977d134a9f8e3f8839f42af655b045fc059e (diff) | |
parent | 25874a299ef8037df03ce4ada570bc4e42f9748f (diff) | |
download | talos-op-linux-d10902812c9cd5583130a4ebb9ad19c60b68149d.tar.gz talos-op-linux-d10902812c9cd5583130a4ebb9ad19c60b68149d.zip |
Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (27 commits)
x86: Clean up apic.c and apic.h
x86: Remove superflous goal definition of tsc_sync
x86: dt: Correct local apic documentation in device tree bindings
x86: dt: Cleanup local apic setup
x86: dt: Fix OLPC=y/INTEL_CE=n build
rtc: cmos: Add OF bindings
x86: ce4100: Use OF to setup devices
x86: ioapic: Add OF bindings for IO_APIC
x86: dtb: Add generic bus probe
x86: dtb: Add support for PCI devices backed by dtb nodes
x86: dtb: Add device tree support for HPET
x86: dtb: Add early parsing of IO_APIC
x86: dtb: Add irq domain abstraction
x86: dtb: Add a device tree for CE4100
x86: Add device tree support
x86: e820: Remove conditional early mapping in parse_e820_ext
x86: OLPC: Make OLPC=n build again
x86: OLPC: Remove extra OLPC_OPENFIRMWARE_DT indirection
x86: OLPC: Cleanup config maze completely
x86: OLPC: Hide OLPC_OPENFIRMWARE config switch
...
Fix up conflicts in arch/x86/platform/ce4100/ce4100.c
Diffstat (limited to 'arch/x86/kernel/apb_timer.c')
-rw-r--r-- | arch/x86/kernel/apb_timer.c | 60 |
1 files changed, 4 insertions, 56 deletions
diff --git a/arch/x86/kernel/apb_timer.c b/arch/x86/kernel/apb_timer.c index 51d4e1663066..1293c709ee85 100644 --- a/arch/x86/kernel/apb_timer.c +++ b/arch/x86/kernel/apb_timer.c @@ -508,64 +508,12 @@ static int apbt_next_event(unsigned long delta, return 0; } -/* - * APB timer clock is not in sync with pclk on Langwell, which translates to - * unreliable read value caused by sampling error. the error does not add up - * overtime and only happens when sampling a 0 as a 1 by mistake. so the time - * would go backwards. the following code is trying to prevent time traveling - * backwards. little bit paranoid. - */ static cycle_t apbt_read_clocksource(struct clocksource *cs) { - unsigned long t0, t1, t2; - static unsigned long last_read; - -bad_count: - t1 = apbt_readl(phy_cs_timer_id, - APBTMR_N_CURRENT_VALUE); - t2 = apbt_readl(phy_cs_timer_id, - APBTMR_N_CURRENT_VALUE); - if (unlikely(t1 < t2)) { - pr_debug("APBT: read current count error %lx:%lx:%lx\n", - t1, t2, t2 - t1); - goto bad_count; - } - /* - * check against cached last read, makes sure time does not go back. - * it could be a normal rollover but we will do tripple check anyway - */ - if (unlikely(t2 > last_read)) { - /* check if we have a normal rollover */ - unsigned long raw_intr_status = - apbt_readl_reg(APBTMRS_RAW_INT_STATUS); - /* - * cs timer interrupt is masked but raw intr bit is set if - * rollover occurs. then we read EOI reg to clear it. - */ - if (raw_intr_status & (1 << phy_cs_timer_id)) { - apbt_readl(phy_cs_timer_id, APBTMR_N_EOI); - goto out; - } - pr_debug("APB CS going back %lx:%lx:%lx ", - t2, last_read, t2 - last_read); -bad_count_x3: - pr_debug("triple check enforced\n"); - t0 = apbt_readl(phy_cs_timer_id, - APBTMR_N_CURRENT_VALUE); - udelay(1); - t1 = apbt_readl(phy_cs_timer_id, - APBTMR_N_CURRENT_VALUE); - udelay(1); - t2 = apbt_readl(phy_cs_timer_id, - APBTMR_N_CURRENT_VALUE); - if ((t2 > t1) || (t1 > t0)) { - printk(KERN_ERR "Error: APB CS tripple check failed\n"); - goto bad_count_x3; - } - } -out: - last_read = t2; - return (cycle_t)~t2; + unsigned long current_count; + + current_count = apbt_readl(phy_cs_timer_id, APBTMR_N_CURRENT_VALUE); + return (cycle_t)~current_count; } static int apbt_clocksource_register(void) |