tree 3c5240901655e14b328c6b5084bf2946ddb2a351
parent 4b9347f4dd8eb838011663d40a11eade419d1ebf
author Todd Poynor <toddpoynor@google.com> 1356047460 -0800
committer Andrew Sutherland <dr3wsuth3rland@gmail.com> 1356497520 -0600

cpufreq: interactive: fix race on timer restart on governor start

Starting the governor, or restarting on a hotplugged-in CPU, can race
with the timer start in idle, triggering a BUG on timer already pending.
Start the timer before setting the enable flag, and use enable_sem to
protect the sequence (and ensure correct order of the update to the
enable flag).  Delete any existing timer for safety.

Change-Id: Ife77cf9fe099e8fd8543224cbf148c6722c2ffb0
Reported-by: Francisco Franco <francisco.franco@cloudcar.com>
Signed-off-by: Todd Poynor <toddpoynor@google.com>