hwmon: (gpio-fan) Remove un-necessary speed_index lookup for thermal hook
authorNishanth Menon <nm@ti.com>
Sat, 20 Feb 2016 00:09:51 +0000 (18:09 -0600)
committerGuenter Roeck <linux@roeck-us.net>
Sat, 20 Feb 2016 01:14:25 +0000 (17:14 -0800)
commit000e0949148382c4962489593a2f05504c2a6771
tree0d4ae71256666f3f785bbae7e9f98bf89dab9ccf
parentacc146943957d7418a6846f06e029b2c5e87e0d5
hwmon: (gpio-fan) Remove un-necessary speed_index lookup for thermal hook

Thermal hook gpio_fan_get_cur_state is only interested in knowing
the current speed index that was setup in the system, this is
already available as part of fan_data->speed_index which is always
set by set_fan_speed. Using get_fan_speed_index is useful when we
have no idea about the fan speed configuration (for example during
fan_ctrl_init).

When thermal framework invokes
gpio_fan_get_cur_state=>get_fan_speed_index via gpio_fan_get_cur_state
especially in a polled configuration for thermal governor, we
basically hog the i2c interface to the extent that other functions
fail to get any traffic out :(.

Instead, just provide the last state set in the driver - since the gpio
fan driver is responsible for the fan state immaterial of override, the
fan_data->speed_index should accurately reflect the state.

Fixes: b5cf88e46bad ("(gpio-fan): Add thermal control hooks")
Reported-by: Tony Lindgren <tony@atomide.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Cc: stable@vger.kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
drivers/hwmon/gpio-fan.c