Is anyone using ftrace on DaVinci git with success?

I'm trying to use the irqsoff tracer to look into an irq latency problem on 
DM355, but it seems not to be recording small time changes, jumping in units of 
10ms.

Example partial trace:

ksoftirq-3       0d..1.    0us : finish_task_switch <-trace_hardirqs_on
ksoftirq-3       0d..1.    0us : trace_hardirqs_on <-trace_hardirqs_on
ksoftirq-3       0d..1.    0us : do_softirq <-trace_hardirqs_off
ksoftirq-3       0d.s1.    0us : __do_softirq <-trace_hardirqs_on
ksoftirq-3       0d.s1.    0us : trace_hardirqs_on <-trace_hardirqs_on
ksoftirq-3       0d.s1.    0us!: hrtimer_peek_ahead_timers <-trace_hardirqs_off
ksoftirq-3       0d.s1. 20000us : hrtimer_peek_ahead_timers <-trace_hardirqs_on
ksoftirq-3       0d.s1. 20000us : trace_hardirqs_on <-trace_hardirqs_on
ksoftirq-3       0d.s1. 20000us : <stack trace>

Related, I have an IRQ handler that seems to be getting interrupted for up to 
2+ms by something. This surprises me, I thought IRQs should be disabled? I 
wonder if CONFIG_PREEMPT is related?

Any hints welcome. For now I suppose I'll go back to poking around with LED 
wiggling and logic analyser.

--
Jon Povey
jon.po...@racelogic.co.uk

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