Commit 7a7d6d9c authored by Benjamin Tissoires's avatar Benjamin Tissoires Committed by Jiri Kosina

HID: i2c-hid: add mutex protecting open/close race

We should not enter close function while someone else is in open.
This mutex prevents this race.

There is also no need to override the ret value with -EIO in case of
a failure of i2c_hid_set_power.
Signed-off-by: default avatarBenjamin Tissoires <benjamin.tissoires@gmail.com>
Reviewed-by: default avatarJean Delvare <khali@linux-fr.org>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent 9afd09a1
......@@ -33,6 +33,7 @@
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/hid.h>
#include <linux/mutex.h>
#include <linux/i2c/i2c-hid.h>
......@@ -117,6 +118,8 @@ static const struct i2c_hid_cmd hid_set_power_cmd = { I2C_HID_CMD(0x08) };
* static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
*/
static DEFINE_MUTEX(i2c_hid_open_mut);
/* The main device structure */
struct i2c_hid {
struct i2c_client *client; /* i2c client */
......@@ -641,17 +644,20 @@ static int i2c_hid_open(struct hid_device *hid)
{
struct i2c_client *client = hid->driver_data;
struct i2c_hid *ihid = i2c_get_clientdata(client);
int ret;
int ret = 0;
mutex_lock(&i2c_hid_open_mut);
if (!hid->open++) {
ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
if (ret) {
hid->open--;
return -EIO;
goto done;
}
set_bit(I2C_HID_STARTED, &ihid->flags);
}
return 0;
done:
mutex_unlock(&i2c_hid_open_mut);
return ret;
}
static void i2c_hid_close(struct hid_device *hid)
......@@ -663,12 +669,14 @@ static void i2c_hid_close(struct hid_device *hid)
* data acquistion due to a resumption we no longer
* care about
*/
mutex_lock(&i2c_hid_open_mut);
if (!--hid->open) {
clear_bit(I2C_HID_STARTED, &ihid->flags);
/* Save some power */
i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
}
mutex_unlock(&i2c_hid_open_mut);
}
static int i2c_hid_power(struct hid_device *hid, int lvl)
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment