On Saturday 11 December 2021 16:54:22 Armin Wolf wrote:
> 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@xxxxxx>
Reviewed-by: Pali Rohár <pali@xxxxxxxxxx>
> ---
> drivers/hwmon/dell-smm-hwmon.c | 28 +++++++++-------------------
> 1 file changed, 9 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c
> index 186d40938036..d8c6e75bb374 100644
> --- 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.
> */
> --
> 2.30.2
>
