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From: "tip-bot2 for Shuah Khan" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Shuah Khan <skhan@linuxfoundation.org>,
	"Peter Zijlstra (Intel)" <peterz@infradead.org>,
	Kalle Valo <kvalo@codeaurora.org>,
	x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [tip: locking/core] ath10k: Detect conf_mutex held ath10k_drain_tx() calls
Date: Wed, 03 Mar 2021 08:15:58 -0000	[thread overview]
Message-ID: <161475935878.20312.1052815878297335176.tip-bot2@tip-bot2> (raw)

The following commit has been merged into the locking/core branch of tip:

Commit-ID:     de469d82991b905548b5dc6539177f7b881dce1b
Gitweb:        https://git.kernel.org/tip/de469d82991b905548b5dc6539177f7b881dce1b
Author:        Shuah Khan <skhan@linuxfoundation.org>
AuthorDate:    Fri, 26 Feb 2021 17:07:00 -07:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Tue, 02 Mar 2021 15:06:35 +01:00

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: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/linux-wireless/871rdmu9z9.fsf@codeaurora.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 bb6c5ee..5ce4f8d 100644
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -4727,6 +4727,8 @@ out:
 /* 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();
 

             reply	other threads:[~2021-03-03 13:11 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-03  8:15 tip-bot2 for Shuah Khan [this message]
2021-03-06 11:54 [tip: locking/core] ath10k: Detect conf_mutex held ath10k_drain_tx() calls tip-bot2 for Shuah Khan

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