On 10 November 2015 at 14:31, Grant Likely <grant.likely@linaro.org> wrote:

After doing a bunch of testing here at home, I've got 22ohm resistors
in series on the i2c, but I didn't add them to the SPI lines. The SPI
lines are driven through a push-pull driver, will it still be
necessary to have in-line resistors for SPI?

Not an EE but the SPI designs I've seen with long traces have had them due to reflections.