Messages in this thread | | | From | Robert Jarzmik <> | Subject | Re: [PATCH v2 1/3] net: irda: pxaficp_ir: use sched_clock() for time management | Date | Wed, 16 Sep 2015 11:34:01 +0200 |
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David Miller <davem@davemloft.net> writes:
> From: Robert Jarzmik <robert.jarzmik@free.fr> > Date: Sat, 12 Sep 2015 13:45:22 +0200 > >> Instead of using directly the OS timer through direct register access, >> use the standard sched_clock(), which will end up in OSCR reading >> anyway. >> >> This is a first step for direct access register removal and machine >> specific code removal from this driver. >> >> Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> > > What is the granularity of the OSCR register? It's 307ns (ie. 3.25MHz clock).
> If it is not nanoseconds, then you need to adjust calculations > such as this one: Tell me if the 307ns requires something I should adjust.
My understanding is that the flow will be : sched_clock() rd->read_sched_clock() (cyc_to_ns() transformed for return) pxa_read_sched_clock() readl_relaxed(OSCR)
I didn't see any timings issue, as the flow looks equivalent to the readl(OSCR), but I might have overlooked something.
Cheers.
-- Robert
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