Rid of CONFIG_DISABLE_TIME_ADJUST
time: Fix accumulation bug triggered by long delay.

The logarithmic accumulation done in the timekeeping has some overflow
protection that limits the max shift value. That means it will take
more then shift loops to accumulate all of the cycles. This causes
the shift decrement to underflow, which causes the loop to never exit.

The simplest fix would be simply to do a:
	if (shift)
		shift--;

However that is not optimal, as we know the cycle offset is larger
then the interval << shift, the above would make shift drop to zero,
then we would be spinning for quite awhile accumulating at interval
chunks at a time.

Instead, this patch only decreases shift if the offset is smaller
then cycle_interval << shift.  This makes sure we accumulate using
the largest chunks possible without overflowing tick_length, and limits
the number of iterations through the loop.

This issue was found and reported by Sonic Zhang, who also tested the fix.
Many thanks your explanation and testing!

Reported-by: Sonic Zhang <sonic.adi@gmail.com>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Tested-by: Sonic Zhang <sonic.adi@gmail.com>
LKML-Reference: <1268948850-5225-1-git-send-email-johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
timekeeping: Fix overflow in rawtime tv_nsec on 32 bit archs

The tv_nsec is a long and when added to the shifted interval it can wrap
and become negative which later causes looping problems in the
getrawmonotonic().  The edge case occurs when the system has slept for
a short period of time of ~2 seconds.

A trace printk of the values in this patch illustrate the problem:

ftrace time stamp: log
43.716079: logarithmic_accumulation: raw: 3d0913 tv_nsec d687faa
43.718513: logarithmic_accumulation: raw: 3d0913 tv_nsec da588bd
43.722161: logarithmic_accumulation: raw: 3d0913 tv_nsec de291d0
46.349925: logarithmic_accumulation: raw: 7a122600 tv_nsec e1f9ae3
46.349930: logarithmic_accumulation: raw: 1e848980 tv_nsec 8831c0e3

The kernel starts looping at 46.349925 in the getrawmonotonic() due to
the negative value from adding the raw value to tv_nsec.

A simple solution is to accumulate into a u64, and then normalize it
to a timespec_t.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
 [ Reworked variable names and simplified some of the code. - John ]
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
time: Workaround gcc loop optimization that causes 64bit div errors

Early 4.3 versions of gcc apparently aggressively optimize the raw
time accumulation loop, replacing it with a divide.

On 32bit systems, this causes the following link errors:
	undefined reference to `__umoddi3'
	undefined reference to `__udivdi3'

The gcc issue has been fixed in 4.4 and greater.

This patch replaces the accumulation loop with a do_div, as suggested
by Linus.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
CC: Jason Wessel <jason.wessel@windriver.com>
CC: Larry Finger <Larry.Finger@lwfinger.net>
CC: Ingo Molnar <mingo@elte.hu>
CC: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
time: Compensate for rounding on odd-frequency clocksources

When the clocksource is not a multiple of HZ, the clock will be off.  For
acpi_pm, HZ=1000 the error is 127.111 ppm:

The rounding of cycle_interval ends up generating a false error term in
ntp_error accumulation since xtime_interval is not exactly 1/HZ.  So, we
subtract out the error caused by the rounding.

This has been visible since 2.6.32-rc2
	commit a092ff0f90cae22b2ac8028ecd2c6f6c1a9e4601
	time: Implement logarithmic time accumulation
That commit raised NTP_INTERVAL_FREQ and exposed the rounding error.

testing tool: http://n1.taur.dk/permanent/testpmt.c
Also tested with ntpd and a frequency counter.

Signed-off-by: Kasper Pedersen <kkp2010@kasperkp.dk>
Acked-by: john stultz <johnstul@us.ibm.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Improve crash reports
stellaris: fix adc conversion expressions