GitLab

BugLink: http://bugs.launchpad.net/bugs/1520436



The LPSS PWM driver calls pwm_lpss_disable() when the PWM device is
released (for example unexported from sysfs). This in turn calls
pm_runtime_put() which makes runtime PM count to be unbalanced if the
device has not been enabled at this point.

This is easy to reproduce:

  # cd /sys/class/pwm/pwmchip0
  # echo 0 > export
  # echo 0 > unexport

The count is unbalanced and prevents the PWM device from being powered on
next time.

Fix this by removing ->free() callback. There are no resources to be
released anyway.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
(cherry picked from commit c7b91b33

)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>