Friday 15 May 2015

Yosemite and Latency II - More Problems

Last week I had a customer report more problems with Yosemite so I tried to replicate my last results - and failed! I then re-installed Yosemite from scratch and still failed!

To help make tests I wrote a small test program which measures the total time to send and receive a message.
 http://www.colinbroad.com/cbsoft/usb422/latency-mac.zip
Note: It is the maximum time that is of interest.

On investigation I discovered with the help of others that Yosemite requires signed drivers, if you rename the kext files or edit the plist file it disables the signing and the driver will no longer install.

I am now waiting for certification from Apple which will take 7 - 10 days assuming that they approve my application. If I get certification I will build a certified driver.

There is one alternative if you need it now, you can run a uncertified driver by disabling the gatekeeper which will then allow uncertified drivers to run. Wolfgang at SMM has confirmed this works.  Note: this allows any uncertified program to run with out confirmation.