From: Sujith Manoharan <c_manoha@xxxxxxxxxxxxxxxx>
When a HW reset is done, the interrupt tasklet is
disabled before ISRs are disabled in the HW. This
allows a small window where the HW can still generate
interrupts. Since the tasklet is disabled and not killed,
it is not scheduled but deferred for execution at a later
time.
This happens because ATH_OP_HW_RESET is not set when ath_reset()
is called. When the hw_reset_work workqueue is used, this
problem doesn't arise because ATH_OP_HW_RESET is set
and the ISR bails out.
Set ATH_OP_HW_RESET properly in ath_reset() to avoid
this race - all the ath_reset_internal() callers have
been converted to use ath_reset() in the previous patch.
Signed-off-by: Sujith Manoharan <c_manoha@xxxxxxxxxxxxxxxx>
---
drivers/net/wireless/ath/ath9k/main.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index eb6ba9f..dda09ba 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -598,10 +598,17 @@ chip_reset:
#undef SCHED_INTR
}
+/*
+ * This function is called when a HW reset cannot be deferred
+ * and has to be immediate.
+ */
int ath_reset(struct ath_softc *sc, struct ath9k_channel *hchan)
{
+ struct ath_common *common = ath9k_hw_common(sc->sc_ah);
int r;
+ set_bit(ATH_OP_HW_RESET, &common->op_flags);
+
ath9k_ps_wakeup(sc);
r = ath_reset_internal(sc, hchan);
ath9k_ps_restore(sc);
@@ -609,6 +616,11 @@ int ath_reset(struct ath_softc *sc, struct ath9k_channel *hchan)
return r;
}
+/*
+ * When a HW reset can be deferred, it is added to the
+ * hw_reset_work workqueue, but we set ATH_OP_HW_RESET before
+ * queueing.
+ */
void ath9k_queue_reset(struct ath_softc *sc, enum ath_reset_type type)
{
struct ath_common *common = ath9k_hw_common(sc->sc_ah);
--
2.1.2
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