From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1428892AbcBTAMV (ORCPT ); Fri, 19 Feb 2016 19:12:21 -0500 Received: from bear.ext.ti.com ([192.94.94.41]:32815 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1424220AbcBTAMT (ORCPT ); Fri, 19 Feb 2016 19:12:19 -0500 From: Nishanth Menon To: Guenter Roeck , Jean Delvare CC: Tony Lindgren , , , , , Nishanth Menon , Eduardo Valentin Subject: [PATCH] hwmon: (gpio-fan) Remove un-necessary speed_index lookup for thermal hook Date: Fri, 19 Feb 2016 18:09:51 -0600 Message-ID: <1455926991-15189-1-git-send-email-nm@ti.com> X-Mailer: git-send-email 1.7.9.5 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Cc: Guenter Roeck Cc: Eduardo Valentin Signed-off-by: Nishanth Menon --- 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; } -- 2.7.0