Commit bdb1050e authored by Shuah Khan's avatar Shuah Khan Committed by Ingo Molnar
Browse files

ath10k: Detect conf_mutex held ath10k_drain_tx() calls 



ath10k_drain_tx() must not be called with conf_mutex held as workers can
use that also. Add call to lockdep_assert_not_held() on conf_mutex to
detect if conf_mutex is held by the caller.

The idea for this patch stemmed from coming across the comment block
above the ath10k_drain_tx() while reviewing the conf_mutex holds during
to debug the conf_mutex lock assert in ath10k_debug_fw_stats_request().

Adding detection to assert on conf_mutex hold will help detect incorrect
usages that could lead to locking problems when async worker routines try
to call this routine.

Signed-off-by: default avatarShuah Khan <skhan@linuxfoundation.org>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Acked-by: default avatarKalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/linux-wireless/871rdmu9z9.fsf@codeaurora.org/
parent f8cfa466

drivers/net/wireless/ath/ath10k/mac.c

+2 −0
Original line number Diff line number Diff line
@@ -4727,6 +4727,8 @@ static void ath10k_mac_op_wake_tx_queue(struct ieee80211_hw *hw, 
/* Must not be called with conf_mutex held as workers can use that also. */

void ath10k_drain_tx(struct ath10k *ar)

{

	lockdep_assert_not_held(&ar->conf_mutex);



	/* make sure rcu-protected mac80211 tx path itself is drained */

	synchronize_net();