iwlwifi: fw: fix notification wait locking

Since we now call iwl_notification_wait_notify() from the
NAPI poll in soft-IRQ, we get a (valid) lockdep complaint
that we could get a deadlock by taking the spinlock from
sleeping context and then getting the soft-IRQ that also
tries to take it (in NAPI polling).

Fix this by disabling soft-IRQs for this lock.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Fixes: 25edc8f259c7 ("iwlwifi: pcie: properly implement NAPI")
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/iwlwifi.20210326125611.c3b2e3d6b58b.Ic56f351d04674df70567bab0269cba91bdbc853c@changeid

diff --git a/drivers/net/wireless/intel/iwlwifi/fw/notif-wait.c b/drivers/net/wireless/intel/iwlwifi/fw/notif-wait.c
index 3dbc6f3..231d251 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/fw/notif-wait.c
+++ b/drivers/net/wireless/intel/iwlwifi/fw/notif-wait.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
 /*
- * Copyright (C) 2005-2014 Intel Corporation
+ * Copyright (C) 2005-2014, 2021 Intel Corporation
  * Copyright (C) 2015-2017 Intel Deutschland GmbH
  */
 #include <linux/sched.h>
@@ -26,7 +26,7 @@ bool iwl_notification_wait(struct iwl_notif_wait_data *notif_wait,
        if (!list_empty(&notif_wait->notif_waits)) {
                struct iwl_notification_wait *w;
 
-               spin_lock(&notif_wait->notif_wait_lock);
+               spin_lock_bh(&notif_wait->notif_wait_lock);
                list_for_each_entry(w, &notif_wait->notif_waits, list) {
                        int i;
                        bool found = false;
@@ -59,7 +59,7 @@ bool iwl_notification_wait(struct iwl_notif_wait_data *notif_wait,
                                triggered = true;
                        }
                }
-               spin_unlock(&notif_wait->notif_wait_lock);
+               spin_unlock_bh(&notif_wait->notif_wait_lock);
        }
 
        return triggered;
@@ -70,10 +70,10 @@ void iwl_abort_notification_waits(struct iwl_notif_wait_data *notif_wait)
 {
        struct iwl_notification_wait *wait_entry;
 
-       spin_lock(&notif_wait->notif_wait_lock);
+       spin_lock_bh(&notif_wait->notif_wait_lock);
        list_for_each_entry(wait_entry, &notif_wait->notif_waits, list)
                wait_entry->aborted = true;
-       spin_unlock(&notif_wait->notif_wait_lock);
+       spin_unlock_bh(&notif_wait->notif_wait_lock);
 
        wake_up_all(&notif_wait->notif_waitq);
 }