greybus: hid: remove custom locking from gb_hid_open/close

Now that HID core enforces serialization of transport driver open/close
calls we can remove custom locking from greybus hid driver.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/drivers/staging/greybus/hid.c b/drivers/staging/greybus/hid.c
index 730d746..465101b 100644 (file)
--- a/drivers/staging/greybus/hid.c
+++ b/drivers/staging/greybus/hid.c
@@ -32,8 +32,6 @@ struct gb_hid {
        char                            *inbuf;
 };
 
-static DEFINE_MUTEX(gb_hid_open_mutex);
-
 /* Routines to get controller's information over greybus */
 
 /* Operations performed on greybus */
@@ -346,19 +344,14 @@ static void gb_hid_stop(struct hid_device *hid)
 static int gb_hid_open(struct hid_device *hid)
 {
        struct gb_hid *ghid = hid->driver_data;
-       int ret = 0;
-
-       mutex_lock(&gb_hid_open_mutex);
-       if (!hid->open++) {
-               ret = gb_hid_set_power(ghid, GB_HID_TYPE_PWR_ON);
-               if (ret < 0)
-                       hid->open--;
-               else
-                       set_bit(GB_HID_STARTED, &ghid->flags);
-       }
-       mutex_unlock(&gb_hid_open_mutex);
+       int ret;
 
-       return ret;
+       ret = gb_hid_set_power(ghid, GB_HID_TYPE_PWR_ON);
+       if (ret < 0)
+               return ret;
+
+       set_bit(GB_HID_STARTED, &ghid->flags);
+       return 0;
 }
 
 static void gb_hid_close(struct hid_device *hid)
@@ -366,21 +359,13 @@ static void gb_hid_close(struct hid_device *hid)
        struct gb_hid *ghid = hid->driver_data;
        int ret;
 
-       /*
-        * Protecting hid->open to make sure we don't restart data acquistion
-        * due to a resumption we no longer care about..
-        */
-       mutex_lock(&gb_hid_open_mutex);
-       if (!--hid->open) {
-               clear_bit(GB_HID_STARTED, &ghid->flags);
-
-               /* Save some power */
-               ret = gb_hid_set_power(ghid, GB_HID_TYPE_PWR_OFF);
-               if (ret)
-                       dev_err(&ghid->connection->bundle->dev,
-                               "failed to power off (%d)\n", ret);
-       }
-       mutex_unlock(&gb_hid_open_mutex);
+       clear_bit(GB_HID_STARTED, &ghid->flags);
+
+       /* Save some power */
+       ret = gb_hid_set_power(ghid, GB_HID_TYPE_PWR_OFF);
+       if (ret)
+               dev_err(&ghid->connection->bundle->dev,
+                       "failed to power off (%d)\n", ret);
 }
 
 static int gb_hid_power(struct hid_device *hid, int lvl)