| Message ID | 1355331602-1164-1-git-send-email-benjamin.tissoires@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Jiri Kosina |
| Headers | show |
On Wed, 12 Dec 2012, Benjamin Tissoires wrote: > 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: Benjamin Tissoires <benjamin.tissoires@gmail.com> > Reviewed-by: Jean Delvare <khali@linux-fr.org> > --- > > Changes in v2: > * add mutex.h Applied, thanks. > > Cheers, > Benjamin > > drivers/hid/i2c-hid/i2c-hid.c | 14 +++++++++++--- > 1 file changed, 11 insertions(+), 3 deletions(-) > > diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c > index 6e1774c..9ef22244 100644 > --- a/drivers/hid/i2c-hid/i2c-hid.c > +++ b/drivers/hid/i2c-hid/i2c-hid.c > @@ -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) > -- > 1.8.0.2 >
diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c index 6e1774c..9ef22244 100644 --- a/drivers/hid/i2c-hid/i2c-hid.c +++ b/drivers/hid/i2c-hid/i2c-hid.c @@ -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)