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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
This commit is contained in:
Johannes Berg 2013-10-02 12:05:24 +02:00
parent 911222b57b
commit 3dd1cd2d33
1 changed files with 3 additions and 6 deletions
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9
drivers/net/wireless/iwlwifi/mvm/bt-coex.c
View File

@ -602,15 +602,15 @@ void iwl_mvm_bt_rssi_event(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
};
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 @@ void iwl_mvm_bt_rssi_event(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
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)