Re: [PATCH] Round the calculated scale factor in set_cyc2ns_scale()
From: John Stultz
Date: Wed Dec 19 2012 - 13:28:37 EST
On 12/05/2012 06:16 AM, Bernd Faust wrote:
During some experiments with an external clock (in a FPGA), we saw that
the TSC clock drifted approx. 2.5ms per second.
This drift was caused by the current way of calculating the scale.
In our case cpu_khz had a value of 3292725. This resulted in a scale
value of 310. But when doing the calculation by hand it shows that the
actual value is 310.9886188491, so a value of 311 would be more precise.
With this change the value is rounded.
Signed-off-by: Bernd Faust <berndfaust@xxxxxxxxx>
Thanks for sending this in! I've queued it, but because I was slow here,
it will have to wait for 3.9.
Sorry for the delay, and thanks again!
-john
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/