Return-path: Received: from nbd.name ([46.4.11.11]:36684 "EHLO nbd.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752727Ab1CJAfJ (ORCPT ); Wed, 9 Mar 2011 19:35:09 -0500 From: Felix Fietkau To: linux-wireless@vger.kernel.org Cc: linville@tuxdriver.com, lrodriguez@atheros.com Subject: [PATCH 2/4] ath9k: fix stopping tx dma on reset Date: Thu, 10 Mar 2011 01:35:01 +0100 Message-Id: <1299717303-42430-2-git-send-email-nbd@openwrt.org> In-Reply-To: <1299717303-42430-1-git-send-email-nbd@openwrt.org> References: <1299717303-42430-1-git-send-email-nbd@openwrt.org> Sender: linux-wireless-owner@vger.kernel.org List-ID: 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 --- 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