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@xxxxxxxxxxxxxxxxxxx>
AuthorDate: Fri, 26 Feb 2021 17:07:00 -07:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Acked-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/linux-wireless/871rdmu9z9.fsf@xxxxxxxxxxxxxx/
---
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();
|