diff options
| -rw-r--r-- | net/rfkill/rfkill.c | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/net/rfkill/rfkill.c b/net/rfkill/rfkill.c index 35a9994e2339..1f23de20a85e 100644 --- a/net/rfkill/rfkill.c +++ b/net/rfkill/rfkill.c @@ -525,17 +525,44 @@ static struct class rfkill_class = { .dev_uevent = rfkill_dev_uevent, }; +static int rfkill_check_duplicity(const struct rfkill *rfkill) +{ + struct rfkill *p; + unsigned long seen[BITS_TO_LONGS(RFKILL_TYPE_MAX)]; + + memset(seen, 0, sizeof(seen)); + + list_for_each_entry(p, &rfkill_list, node) { + if (p == rfkill) { + WARN_ON(1); + return -EEXIST; + } + set_bit(p->type, seen); + } + + /* 0: first switch of its kind */ + return test_bit(rfkill->type, seen); +} + static int rfkill_add_switch(struct rfkill *rfkill) { + int error; + mutex_lock(&rfkill_mutex); + error = rfkill_check_duplicity(rfkill); + if (error < 0) + goto unlock_out; + rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type], 0); list_add_tail(&rfkill->node, &rfkill_list); + error = 0; +unlock_out: mutex_unlock(&rfkill_mutex); - return 0; + return error; } static void rfkill_remove_switch(struct rfkill *rfkill) |