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Subject[PATCH v2 2/2] hwmon: (dell-smm) Unify i8k_ioctl() and i8k_ioctl_unlocked()
Date
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>
---
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
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