[PATCH 3.2 024/110] ath9k: fix DMA stop sequence for AR9003+

From: Ben Hutchings
Date: Mon Aug 10 2015 - 06:44:58 EST


3.2.71-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Felix Fietkau <nbd@xxxxxxxxxxx>

commit 300f77c08ded96d33f492aaa02549103852f0c12 upstream.

AR93xx and newer needs to stop rx before tx to avoid getting the DMA
engine or MAC into a stuck state.
This should reduce/fix the occurence of "Failed to stop Tx DMA" logspam.

Signed-off-by: Felix Fietkau <nbd@xxxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
[bwh: Backported to 3.2:
- Also move initialisation of ret to match upstream
- ath_drain_all_txq() takes a second parameter]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/net/wireless/ath/ath9k/main.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -235,7 +235,7 @@ static bool ath_prepare_reset(struct ath
{
struct ath_hw *ah = sc->sc_ah;
struct ath_common *common = ath9k_hw_common(ah);
- bool ret;
+ bool ret = true;

ieee80211_stop_queues(sc->hw);

@@ -245,10 +245,13 @@ static bool ath_prepare_reset(struct ath
ath9k_debug_samp_bb_mac(sc);
ath9k_hw_disable_interrupts(ah);

- ret = ath_drain_all_txq(sc, retry_tx);
-
- if (!ath_stoprecv(sc))
- ret = false;
+ if (AR_SREV_9300_20_OR_LATER(ah)) {
+ ret &= ath_stoprecv(sc);
+ ret &= ath_drain_all_txq(sc, retry_tx);
+ } else {
+ ret &= ath_drain_all_txq(sc, retry_tx);
+ ret &= ath_stoprecv(sc);
+ }

if (!flush) {
if (ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/