| Message ID | 1355328736-31418-1-git-send-email-benjamin.tissoires@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Jiri Kosina |
| Headers | show |
Hi Benjamin, On Wed, 12 Dec 2012 17:12:16 +0100, 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> > --- Looks good to me except that you forgot to include <linux/mutex.h> and this could cause build failures on some architectures/configs. Once this is fixed, you can add: Reviewed-by: Jean Delvare <khali@linux-fr.org>
On Wed, Dec 12, 2012 at 5:34 PM, Jean Delvare <khali@linux-fr.org> wrote: > Hi Benjamin, > > On Wed, 12 Dec 2012 17:12:16 +0100, 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> >> --- > > Looks good to me except that you forgot to include <linux/mutex.h> and > this could cause build failures on some architectures/configs. > > Once this is fixed, you can add: > > Reviewed-by: Jean Delvare <khali@linux-fr.org> Thanks, I will resend it right now. Cheers, Benjamin > > -- > Jean Delvare -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c index 6e1774c..74dfc33 100644 --- a/drivers/hid/i2c-hid/i2c-hid.c +++ b/drivers/hid/i2c-hid/i2c-hid.c @@ -117,6 +117,8 @@ 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 +643,20 @@ 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 +668,14 @@ 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)
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> --- Hi Jiri, hi Jean, this is the last patch that came from the last review. Sorry I took so long to do it, but I thought it would have raised other problems. In the end, the changes are pretty straightforward, and it would be great to have this one in 3.8-rc0 too. Anyway, Jiri, the choice is yours. Cheers, Benjamin drivers/hid/i2c-hid/i2c-hid.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)