From: Xing Tong Wu <xingtong.wu@siemens.com>
Date: Tue, 21 Nov 2023 08:16:04 +0000 (+0800)
Subject: hwmon: (nct6775) Fix fan speed set failure in automatic mode
X-Git-Tag: v6.6.17~268
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=6f86bbf92cc5ebb304b1f8be43279354c4285daf;p=platform%2Fkernel%2Flinux-starfive.git

hwmon: (nct6775) Fix fan speed set failure in automatic mode

[ Upstream commit 8b3800256abad20e91c2698607f9b28591407b19 ]

Setting the fan speed is only valid in manual mode; it is not possible
to set the fan's speed in automatic mode.
Return error when attempting to set the fan speed in automatic mode.

Signed-off-by: Xing Tong Wu <xingtong.wu@siemens.com>
Link: https://lore.kernel.org/r/20231121081604.2499-3-xingtong_wu@163.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/hwmon/nct6775-core.c b/drivers/hwmon/nct6775-core.c
index d928eb8..92a49fa 100644
--- a/drivers/hwmon/nct6775-core.c
+++ b/drivers/hwmon/nct6775-core.c
@@ -2553,6 +2553,13 @@ store_pwm(struct device *dev, struct device_attribute *attr, const char *buf,
 	int err;
 	u16 reg;
 
+	/*
+	 * The fan control mode should be set to manual if the user wants to adjust
+	 * the fan speed. Otherwise, it will fail to set.
+	 */
+	if (index == 0 && data->pwm_enable[nr] > manual)
+		return -EBUSY;
+
 	err = kstrtoul(buf, 10, &val);
 	if (err < 0)
 		return err;