[patch 10/14] ath9k: Use tasklet_disable_in_atomic()

From: Thomas Gleixner
Date: Tue Mar 09 2021 - 03:46:44 EST


From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>

All callers of ath9k_beacon_ensure_primary_slot() are preemptible /
acquire a mutex except for this callchain:

spin_lock_bh(&sc->sc_pcu_lock);
ath_complete_reset()
-> ath9k_calculate_summary_state()
-> ath9k_beacon_ensure_primary_slot()

It's unclear how that can be distangled, so use tasklet_disable_in_atomic()
for now. This allows tasklet_disable() to become sleepable once the
remaining atomic users are cleaned up.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: ath9k-devel@xxxxxxxxxxxxxxxx
Cc: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: linux-wireless@xxxxxxxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
---
drivers/net/wireless/ath/ath9k/beacon.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/wireless/ath/ath9k/beacon.c
+++ b/drivers/net/wireless/ath/ath9k/beacon.c
@@ -251,7 +251,7 @@ void ath9k_beacon_ensure_primary_slot(st
int first_slot = ATH_BCBUF;
int slot;

- tasklet_disable(&sc->bcon_tasklet);
+ tasklet_disable_in_atomic(&sc->bcon_tasklet);

/* Find first taken slot. */
for (slot = 0; slot < ATH_BCBUF; slot++) {