ath9k: fix race condition in enabling/disabling IRQs

The code currently relies on refcounting to disable IRQs from within the
IRQ handler and re-enabling them again after the tasklet has run.

However, due to race conditions sometimes the IRQ handler might be
called twice, or the tasklet may not run at all (if interrupted in the
middle of a reset).

This can cause nasty imbalances in the irq-disable refcount which will
get the driver permanently stuck until the entire radio has been stopped
and started again (ath_reset will not recover from this).

Instead of using this fragile logic, change the code to ensure that
running the irq handler during tasklet processing is safe, and leave the
refcount untouched.

Cc: stable@vger.kernel.org
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath9k/mac.h b/drivers/net/wireless/ath/ath9k/mac.h
index 3bab01435a86..770fc11b41d1 100644
--- a/drivers/net/wireless/ath/ath9k/mac.h
+++ b/drivers/net/wireless/ath/ath9k/mac.h
@@ -744,6 +744,7 @@ void ath9k_hw_set_interrupts(struct ath_hw *ah);
 void ath9k_hw_enable_interrupts(struct ath_hw *ah);
 void ath9k_hw_disable_interrupts(struct ath_hw *ah);
 void ath9k_hw_kill_interrupts(struct ath_hw *ah);
+void ath9k_hw_resume_interrupts(struct ath_hw *ah);
 
 void ar9002_hw_attach_mac_ops(struct ath_hw *ah);