| Message ID | 1455926991-15189-1-git-send-email-nm@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 02/19/2016 04:09 PM, Nishanth Menon wrote: > 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> > --- Applied. Thanks, Guenter > Test logs from linus master v4.5-rc4-137-g23300f657594 > Without fix: http://paste.ubuntu.org.cn/3948618 > With Fix: http://paste.ubuntu.org.cn/3948617 > > drivers/hwmon/gpio-fan.c | 7 +------ > 1 file changed, 1 insertion(+), 6 deletions(-) > > diff --git a/drivers/hwmon/gpio-fan.c b/drivers/hwmon/gpio-fan.c > index 82de3deeb18a..685568b1236d 100644 > --- a/drivers/hwmon/gpio-fan.c > +++ b/drivers/hwmon/gpio-fan.c > @@ -406,16 +406,11 @@ static int gpio_fan_get_cur_state(struct thermal_cooling_device *cdev, > unsigned long *state) > { > struct gpio_fan_data *fan_data = cdev->devdata; > - int r; > > if (!fan_data) > return -EINVAL; > > - r = get_fan_speed_index(fan_data); > - if (r < 0) > - return r; > - > - *state = r; > + *state = fan_data->speed_index; > return 0; > } > > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/hwmon/gpio-fan.c b/drivers/hwmon/gpio-fan.c index 82de3deeb18a..685568b1236d 100644 --- a/drivers/hwmon/gpio-fan.c +++ b/drivers/hwmon/gpio-fan.c @@ -406,16 +406,11 @@ static int gpio_fan_get_cur_state(struct thermal_cooling_device *cdev, unsigned long *state) { struct gpio_fan_data *fan_data = cdev->devdata; - int r; if (!fan_data) return -EINVAL; - r = get_fan_speed_index(fan_data); - if (r < 0) - return r; - - *state = r; + *state = fan_data->speed_index; return 0; }
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> --- Test logs from linus master v4.5-rc4-137-g23300f657594 Without fix: http://paste.ubuntu.org.cn/3948618 With Fix: http://paste.ubuntu.org.cn/3948617 drivers/hwmon/gpio-fan.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-)