hwmon: (corsair-psu) Rely on subsystem locking

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <[e-mail]>

drivers/hwmon/corsair-psu.c

···
 #include <linux/errno.h>
 #include <linux/hid.h>
 #include <linux/hwmon.h>
-#include <linux/hwmon-sysfs.h>
 #include <linux/jiffies.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
-#include <linux/mutex.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 
···
 	struct device *hwmon_dev;
 	struct dentry *debugfs;
 	struct completion wait_completion;
-	struct mutex lock; /* for locking access to cmd_buffer */
 	u8 *cmd_buffer;
 	char vendor[REPLY_SIZE];
 	char product[REPLY_SIZE];
···
 {
 	int ret;
 
-	mutex_lock(&priv->lock);
 	switch (cmd) {
 	case PSU_CMD_RAIL_VOLTS_HCRIT:
 	case PSU_CMD_RAIL_VOLTS_LCRIT:
···
 	case PSU_CMD_RAIL_WATTS:
 		ret = corsairpsu_usb_cmd(priv, 2, PSU_CMD_SELECT_RAIL, rail, NULL);
 		if (ret < 0)
-			goto cmd_fail;
+			return ret;
 		break;
 	default:
 		break;
 	}
 
-	ret = corsairpsu_usb_cmd(priv, 3, cmd, 0, data);
-
-cmd_fail:
-	mutex_unlock(&priv->lock);
-	return ret;
+	return corsairpsu_usb_cmd(priv, 3, cmd, 0, data);
 }
 
 static int corsairpsu_get_value(struct corsairpsu_data *priv, u8 cmd, u8 rail, long *val)
···
 
 	priv->hdev = hdev;
 	hid_set_drvdata(hdev, priv);
-	mutex_init(&priv->lock);
 	init_completion(&priv->wait_completion);
 
 	hid_device_io_start(hdev);