I have an Overo application that polls 3 devices on an SPI bus and
transfers 48 bits to each device at a rate of 100Hz.
I have been doing this on the old linux kernel 2.6.33 with no issues, but
on the 2.6.34 r88 I have found that this in now pulling a steady 5% CPU in
the omap2_mcspi driver to do this. Is there any known issues that would be
causing this increase in CPU usage on the driver? Under 2.6.33 it pulled a
The only other possible contributing factor is that I am now running the
kernel in CONFIG_PREEMPT more, which I will change back temporarily to see
if this has a significant effect.