pwm: lpss: Remove suspend/resume handlers
authorHans de Goede <hdegoede@redhat.com>
Thu, 3 Sep 2020 11:23:27 +0000 (13:23 +0200)
committerHans de Goede <hdegoede@redhat.com>
Sun, 6 Sep 2020 13:38:01 +0000 (15:38 +0200)
commit547d9e9261d294f0a2597d9e9c55ba48f80716ab
treeceb7f144da1e93e5172336a1e9ba5493bef654a3
parentd6d54bacb1dd02a31ed9d8e3db028639da292615
pwm: lpss: Remove suspend/resume handlers

PWM controller drivers should not restore the PWM state on resume. The
convention is that PWM consumers do this by calling pwm_apply_state(),
so that it can be done at the exact moment when the consumer needs
the state to be stored, avoiding e.g. backlight flickering.

The only in kernel consumers of the pwm-lpss code, the i915 driver
and the pwm-class sysfs interface code both correctly restore the
state on resume, so there is no need to do this in the pwm-lpss code.

More-over the removed resume handler is buggy, since it blindly
restores the ctrl-register contents without setting the update
bit, which is necessary to get the controller to actually use/apply
the restored base-unit and on-time-div values.

Acked-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200903112337.4113-8-hdegoede@redhat.com
drivers/pwm/pwm-lpss-platform.c
drivers/pwm/pwm-lpss.c
drivers/pwm/pwm-lpss.h