In some situations, stopping Tx DMA frequently fails, leading to messages
like this:
ath: Failed to stop TX DMA in 100 msec after killing last frame
ath: Failed to stop TX DMA!
This patch uses a few MAC features to abort DMA globally instead of iterating
over all hardware queues and attempting to stop them individually.
Not only is that faster and works with a shorter timeout, it also makes the
process much more reliable.
With this change, I can no longer trigger these messages on AR9380,
and on AR9280 they become much more rare.
Signed-off-by: Felix Fietkau <nbd@xxxxxxxxxxx>
---
drivers/net/wireless/ath/ath9k/mac.c | 31 +++++++++++++++++++++++++++++++
drivers/net/wireless/ath/ath9k/mac.h | 1 +
drivers/net/wireless/ath/ath9k/xmit.c | 14 ++++++--------
3 files changed, 38 insertions(+), 8 deletions(-)
diff --git a/drivers/net/wireless/ath/ath9k/mac.c b/drivers/net/wireless/ath/ath9k/mac.c
index 5efc869..aa9f646 100644
--- a/drivers/net/wireless/ath/ath9k/mac.c
+++ b/drivers/net/wireless/ath/ath9k/mac.c
@@ -143,6 +143,37 @@ bool ath9k_hw_updatetxtriglevel(struct ath_hw *ah, bool bIncTrigLevel)
}
EXPORT_SYMBOL(ath9k_hw_updatetxtriglevel);
+bool ath9k_hw_abort_tx_dma(struct ath_hw *ah)
+{
+ int i, q;
+
+ REG_WRITE(ah, AR_Q_TXD, AR_Q_TXD_M);
+
+ REG_SET_BIT(ah, AR_PCU_MISC, AR_PCU_FORCE_QUIET_COLL | AR_PCU_CLEAR_VMF);
+ REG_SET_BIT(ah, AR_DIAG_SW, AR_DIAG_FORCE_CH_IDLE_HIGH);
+ REG_SET_BIT(ah, AR_D_GBL_IFS_MISC, AR_D_GBL_IFS_MISC_IGNORE_BACKOFF);
+
+ for (q = 0; q < AR_NUM_QCU; q++) {
+ for (i = 1000; i > 0; i--) {
+ if (!ath9k_hw_numtxpending(ah, q))
+ break;
+
+ udelay(5);
+ }
+ }
+ if (!i)
+ return false;
+
+ REG_CLR_BIT(ah, AR_PCU_MISC, AR_PCU_FORCE_QUIET_COLL | AR_PCU_CLEAR_VMF);
+ REG_CLR_BIT(ah, AR_DIAG_SW, AR_DIAG_FORCE_CH_IDLE_HIGH);
+ REG_CLR_BIT(ah, AR_D_GBL_IFS_MISC, AR_D_GBL_IFS_MISC_IGNORE_BACKOFF);
+
+ REG_WRITE(ah, AR_Q_TXD, 0);
+
+ return true;
+}
+EXPORT_SYMBOL(ath9k_hw_abort_tx_dma);
+
bool ath9k_hw_stoptxdma(struct ath_hw *ah, u32 q)
{
#define ATH9K_TX_STOP_DMA_TIMEOUT 4000 /* usec */
diff --git a/drivers/net/wireless/ath/ath9k/mac.h b/drivers/net/wireless/ath/ath9k/mac.h
index 04d58ae..347ee5f 100644
--- a/drivers/net/wireless/ath/ath9k/mac.h
+++ b/drivers/net/wireless/ath/ath9k/mac.h
@@ -677,6 +677,7 @@ void ath9k_hw_cleartxdesc(struct ath_hw *ah, void *ds);
u32 ath9k_hw_numtxpending(struct ath_hw *ah, u32 q);
bool ath9k_hw_updatetxtriglevel(struct ath_hw *ah, bool bIncTrigLevel);
bool ath9k_hw_stoptxdma(struct ath_hw *ah, u32 q);
+bool ath9k_hw_abort_tx_dma(struct ath_hw *ah);
void ath9k_hw_gettxintrtxqs(struct ath_hw *ah, u32 *txqs);
bool ath9k_hw_set_txq_props(struct ath_hw *ah, int q,
const struct ath9k_tx_queue_info *qinfo);
diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index e16136d..bb1d29e 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -1194,16 +1194,14 @@ bool ath_drain_all_txq(struct ath_softc *sc, bool retry_tx)
if (sc->sc_flags & SC_OP_INVALID)
return true;
- /* Stop beacon queue */
- ath9k_hw_stoptxdma(sc->sc_ah, sc->beacon.beaconq);
+ ath9k_hw_abort_tx_dma(ah);
- /* Stop data queues */
+ /* Check if any queue remains active */
for (i = 0; i < ATH9K_NUM_TX_QUEUES; i++) {
- if (ATH_TXQ_SETUP(sc, i)) {
- txq = &sc->tx.txq[i];
- ath9k_hw_stoptxdma(ah, txq->axq_qnum);
- npend += ath9k_hw_numtxpending(ah, txq->axq_qnum);
- }
+ if (!ATH_TXQ_SETUP(sc, i))
+ continue;
+
+ npend += ath9k_hw_numtxpending(ah, sc->tx.txq[i].axq_qnum);
}
if (npend)
--
1.7.3.2
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