hwmon: (dell-smm) Unify i8k_ioctl() and i8k_ioctl_unlocked()

The only purpose of i8k_ioctl() is to call i8k_ioctl_unlocked()
with i8k_mutex held. Judging from the hwmon code, this mutex
only needs to be held when setting the fan speed/mode, so
the operation of I8K_SET_FAN is guaranteed to be atomic.
Unify both functions and reduce the locking of i8k_mutex
to I8K_SET_FAN.

Tested on a Dell Inspiron 3505.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Reviewed-by: Pali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/20211211155422.16830-3-W_Armin@gmx.de
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c
index 186d409380362a105d09771bdf545033820355c4..d8c6e75bb3745a82ea3b7a891b692811a3af8c3f 100644 (file)
--- a/drivers/hwmon/dell-smm-hwmon.c
+++ b/drivers/hwmon/dell-smm-hwmon.c
@@ -449,12 +449,12 @@ static int i8k_get_power_status(void)
  * Procfs interface
  */
 
-static int
-i8k_ioctl_unlocked(struct file *fp, struct dell_smm_data *data, unsigned int cmd, unsigned long arg)
+static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
 {
-       int val = 0;
-       int speed, err;
+       struct dell_smm_data *data = PDE_DATA(file_inode(fp));
        int __user *argp = (int __user *)arg;
+       int speed, err;
+       int val = 0;
 
        if (!argp)
                return -EINVAL;
@@ -516,11 +516,13 @@ i8k_ioctl_unlocked(struct file *fp, struct dell_smm_data *data, unsigned int cmd
                if (copy_from_user(&speed, argp + 1, sizeof(int)))
                        return -EFAULT;
 
+               mutex_lock(&data->i8k_mutex);
                err = i8k_set_fan(data, val, speed);
                if (err < 0)
-                       return err;
-
-               val = i8k_get_fan_status(data, val);
+                       val = err;
+               else
+                       val = i8k_get_fan_status(data, val);
+               mutex_unlock(&data->i8k_mutex);
                break;
 
        default:
@@ -536,18 +538,6 @@ i8k_ioctl_unlocked(struct file *fp, struct dell_smm_data *data, unsigned int cmd
        return 0;
 }
 
-static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
-{
-       struct dell_smm_data *data = PDE_DATA(file_inode(fp));
-       long ret;
-
-       mutex_lock(&data->i8k_mutex);
-       ret = i8k_ioctl_unlocked(fp, data, cmd, arg);
-       mutex_unlock(&data->i8k_mutex);
-
-       return ret;
-}
-
 /*
  * Print the information for /proc/i8k.
  */