From: Shuah Khan <skhan@linuxfoundation.org>
To: peterz@infradead.org, mingo@redhat.com, will@kernel.org,
kvalo@codeaurora.org, davem@davemloft.net, kuba@kernel.org
Cc: Shuah Khan <skhan@linuxfoundation.org>,
ath10k@lists.infradead.org, linux-wireless@vger.kernel.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v3 3/3] ath10k: detect conf_mutex held ath10k_drain_tx() calls
Date: Fri, 26 Feb 2021 17:07:00 -0700 [thread overview]
Message-ID: <c9c2cd7b79f5551741c063239013919bf0e3f984.1614383025.git.skhan@linuxfoundation.org> (raw)
In-Reply-To: <cover.1614383025.git.skhan@linuxfoundation.org>
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.
Link: https://lore.kernel.org/lkml/37a29c383bff2fb1605241ee6c7c9be3784fb3c6.1613171185.git.skhan@linuxfoundation.org/
Link: https://lore.kernel.org/linux-wireless/871rdmu9z9.fsf@codeaurora.org/
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
drivers/net/wireless/ath/ath10k/mac.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c
index bb6c5ee43ac0..5ce4f8d038b9 100644
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -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();
--
2.27.0
next prev parent reply other threads:[~2021-02-27 0:09 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-27 0:06 [PATCH v3 0/3] Add lockdep_assert_not_held() Shuah Khan
2021-02-27 0:06 ` [PATCH v3 1/3] lockdep: add lockdep_assert_not_held() Shuah Khan
2021-02-27 0:06 ` [PATCH v3 2/3] lockdep: add lockdep lock state defines Shuah Khan
2021-02-27 0:07 ` Shuah Khan [this message]
2021-03-01 8:38 ` [PATCH v3 0/3] Add lockdep_assert_not_held() Peter Zijlstra
2021-03-01 8:45 ` Kalle Valo
2021-03-01 9:36 ` Peter Zijlstra
2021-03-01 11:02 ` Kalle Valo
2021-03-01 16:04 ` Shuah Khan
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