iwlwifi: mvm: fix locking in iwl_mvm_bt_rssi_event()
This will deadlock due to commit 9f34783863bea806
("iwlwifi: mvm: Implement BT coex notifications"):
=============================================
[ INFO: possible recursive locking detected ]
3.5.0 #10 Tainted: G W O
---------------------------------------------
kworker/2:1/5214 is trying to acquire lock:
(&mvm->mutex){+.+.+.}, at: [<ffffffffa03be23e>] iwl_mvm_bt_rssi_event+0x5e/0x210 [iwlmvm]
but task is already holding lock:
(&mvm->mutex){+.+.+.}, at: [<ffffffffa03ab2d9>] iwl_mvm_async_handlers_wk+0x49/0x120 [iwlmvm]
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&mvm->mutex);
lock(&mvm->mutex);
*** DEADLOCK ***
Change-Id: I9104f252b34676e2f7ffcd51166f95367e08a4d9
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-on: https://gerrit.rds.intel.com/21887
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Tested-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Conflicts:
drivers/net/wireless/iwlwifi/mvm/bt-coex.c
diff --git a/drivers/net/wireless/iwlwifi/mvm/bt-coex.c b/drivers/net/wireless/iwlwifi/mvm/bt-coex.c
index bba5947..ef59f84 100644
--- a/drivers/net/wireless/iwlwifi/mvm/bt-coex.c
+++ b/drivers/net/wireless/iwlwifi/mvm/bt-coex.c
@@ -602,15 +602,15 @@
};
int ret;
- mutex_lock(&mvm->mutex);
+ lockdep_assert_held(&mvm->mutex);
/* Rssi update while not associated ?! */
if (WARN_ON_ONCE(mvmvif->ap_sta_id == IWL_MVM_STATION_COUNT))
- goto out_unlock;
+ return;
/* No open connection - reports should be disabled */
if (!BT_MBOX_MSG(&mvm->last_bt_notif, 3, OPEN_CON_2))
- goto out_unlock;
+ return;
IWL_DEBUG_COEX(mvm, "RSSI for %pM is now %s\n", vif->bss_conf.bssid,
rssi_event == RSSI_EVENT_HIGH ? "HIGH" : "LOW");
@@ -641,9 +641,6 @@
if (iwl_mvm_bt_udpate_ctrl_kill_msk(mvm, data.reduced_tx_power))
IWL_ERR(mvm, "Failed to update the ctrl_kill_msk\n");
-
- out_unlock:
- mutex_unlock(&mvm->mutex);
}
void iwl_mvm_bt_coex_vif_assoc(struct iwl_mvm *mvm, struct ieee80211_vif *vif)