[PATCH 3.18 20/50] wil6210: fix deadlock when using fw_no_recovery option

From: Greg Kroah-Hartman
Date: Fri Aug 04 2017 - 19:28:26 EST


3.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Lior David <qca_liord@xxxxxxxxxxxxxxxx>

commit dfb5b098e0f40b68aa07f2ec55f4dd762efefbfa upstream.

When FW crashes with no_fw_recovery option, driver
waits for manual recovery with wil->mutex held, this
can easily create deadlocks.
Fix the problem by moving the wait outside the lock.

Signed-off-by: Lior David <qca_liord@xxxxxxxxxxxxxxxx>
Signed-off-by: Maya Erez <qca_merez@xxxxxxxxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxxxx>
Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/net/wireless/ath/wil6210/main.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)

--- a/drivers/net/wireless/ath/wil6210/main.c
+++ b/drivers/net/wireless/ath/wil6210/main.c
@@ -240,18 +240,19 @@ static void wil_fw_error_worker(struct w

wil->last_fw_recovery = jiffies;

+ wil_info(wil, "fw error recovery requested (try %d)...\n",
+ wil->recovery_count);
+ if (!no_fw_recovery)
+ wil->recovery_state = fw_recovery_running;
+ if (wil_wait_for_recovery(wil) != 0)
+ return;
+
mutex_lock(&wil->mutex);
switch (wdev->iftype) {
case NL80211_IFTYPE_STATION:
case NL80211_IFTYPE_P2P_CLIENT:
case NL80211_IFTYPE_MONITOR:
- wil_info(wil, "fw error recovery requested (try %d)...\n",
- wil->recovery_count);
- if (!no_fw_recovery)
- wil->recovery_state = fw_recovery_running;
- if (0 != wil_wait_for_recovery(wil))
- break;
-
+ /* silent recovery, upper layers will see disconnect */
__wil_down(wil);
__wil_up(wil);
break;