From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from nbd.name ([46.4.11.11]:44273 "EHLO nbd.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755104Ab1DJQcY (ORCPT ); Sun, 10 Apr 2011 12:32:24 -0400 From: Felix Fietkau To: linux-wireless@vger.kernel.org Cc: linville@tuxdriver.com, ath5k-devel@lists.ath5k.org Subject: [PATCH 3/7] ath5k: optimize tx status processing Date: Sun, 10 Apr 2011 18:32:15 +0200 Message-Id: <1302453139-11437-3-git-send-email-nbd@openwrt.org> In-Reply-To: <1302453139-11437-2-git-send-email-nbd@openwrt.org> References: <1302453139-11437-1-git-send-email-nbd@openwrt.org> <1302453139-11437-2-git-send-email-nbd@openwrt.org> Sender: linux-wireless-owner@vger.kernel.org List-ID: Use ACCESS_ONCE to reduce the number of variable reloads on uncached memory Signed-off-by: Felix Fietkau --- drivers/net/wireless/ath/ath5k/desc.c | 37 ++++++++++++++++++-------------- 1 files changed, 21 insertions(+), 16 deletions(-) diff --git a/drivers/net/wireless/ath/ath5k/desc.c b/drivers/net/wireless/ath/ath5k/desc.c index 990a3b4..3758b96 100644 --- a/drivers/net/wireless/ath/ath5k/desc.c +++ b/drivers/net/wireless/ath/ath5k/desc.c @@ -401,32 +401,38 @@ static int ath5k_hw_proc_4word_tx_status(struct ath5k_hw *ah, { struct ath5k_hw_4w_tx_ctl *tx_ctl; struct ath5k_hw_tx_status *tx_status; + u32 txstat0, txstat1, txctl2; tx_ctl = &desc->ud.ds_tx5212.tx_ctl; tx_status = &desc->ud.ds_tx5212.tx_stat; + txstat1 = ACCESS_ONCE(tx_status->tx_status_1); + /* No frame has been send or error */ - if (unlikely(!(tx_status->tx_status_1 & AR5K_DESC_TX_STATUS1_DONE))) + if (unlikely(!(txstat1 & AR5K_DESC_TX_STATUS1_DONE))) return -EINPROGRESS; + txstat0 = ACCESS_ONCE(tx_status->tx_status_0); + txctl2 = ACCESS_ONCE(tx_ctl->tx_control_2); + /* * Get descriptor status */ - ts->ts_tstamp = AR5K_REG_MS(tx_status->tx_status_0, + ts->ts_tstamp = AR5K_REG_MS(txstat0, AR5K_DESC_TX_STATUS0_SEND_TIMESTAMP); - ts->ts_shortretry = AR5K_REG_MS(tx_status->tx_status_0, + ts->ts_shortretry = AR5K_REG_MS(txstat0, AR5K_DESC_TX_STATUS0_SHORT_RETRY_COUNT); - ts->ts_longretry = AR5K_REG_MS(tx_status->tx_status_0, + ts->ts_longretry = AR5K_REG_MS(txstat0, AR5K_DESC_TX_STATUS0_LONG_RETRY_COUNT); - ts->ts_seqnum = AR5K_REG_MS(tx_status->tx_status_1, + ts->ts_seqnum = AR5K_REG_MS(txstat1, AR5K_DESC_TX_STATUS1_SEQ_NUM); - ts->ts_rssi = AR5K_REG_MS(tx_status->tx_status_1, + ts->ts_rssi = AR5K_REG_MS(txstat1, AR5K_DESC_TX_STATUS1_ACK_SIG_STRENGTH); - ts->ts_antenna = (tx_status->tx_status_1 & + ts->ts_antenna = (txstat1 & AR5K_DESC_TX_STATUS1_XMIT_ANTENNA_5212) ? 2 : 1; ts->ts_status = 0; - ts->ts_final_idx = AR5K_REG_MS(tx_status->tx_status_1, + ts->ts_final_idx = AR5K_REG_MS(txstat1, AR5K_DESC_TX_STATUS1_FINAL_TS_IX_5212); /* The longretry counter has the number of un-acked retries @@ -437,17 +443,17 @@ static int ath5k_hw_proc_4word_tx_status(struct ath5k_hw *ah, ts->ts_retry[ts->ts_final_idx] = ts->ts_longretry; switch (ts->ts_final_idx) { case 3: - ts->ts_retry[2] = AR5K_REG_MS(tx_ctl->tx_control_2, + ts->ts_retry[2] = AR5K_REG_MS(txctl2, AR5K_4W_TX_DESC_CTL2_XMIT_TRIES2); ts->ts_longretry += ts->ts_retry[2]; /* fall through */ case 2: - ts->ts_retry[1] = AR5K_REG_MS(tx_ctl->tx_control_2, + ts->ts_retry[1] = AR5K_REG_MS(txctl2, AR5K_4W_TX_DESC_CTL2_XMIT_TRIES1); ts->ts_longretry += ts->ts_retry[1]; /* fall through */ case 1: - ts->ts_retry[0] = AR5K_REG_MS(tx_ctl->tx_control_2, + ts->ts_retry[0] = AR5K_REG_MS(txctl2, AR5K_4W_TX_DESC_CTL2_XMIT_TRIES1); ts->ts_longretry += ts->ts_retry[0]; /* fall through */ @@ -456,15 +462,14 @@ static int ath5k_hw_proc_4word_tx_status(struct ath5k_hw *ah, } /* TX error */ - if (!(tx_status->tx_status_0 & AR5K_DESC_TX_STATUS0_FRAME_XMIT_OK)) { - if (tx_status->tx_status_0 & - AR5K_DESC_TX_STATUS0_EXCESSIVE_RETRIES) + if (!(txstat0 & AR5K_DESC_TX_STATUS0_FRAME_XMIT_OK)) { + if (txstat0 & AR5K_DESC_TX_STATUS0_EXCESSIVE_RETRIES) ts->ts_status |= AR5K_TXERR_XRETRY; - if (tx_status->tx_status_0 & AR5K_DESC_TX_STATUS0_FIFO_UNDERRUN) + if (txstat0 & AR5K_DESC_TX_STATUS0_FIFO_UNDERRUN) ts->ts_status |= AR5K_TXERR_FIFO; - if (tx_status->tx_status_0 & AR5K_DESC_TX_STATUS0_FILTERED) + if (txstat0 & AR5K_DESC_TX_STATUS0_FILTERED) ts->ts_status |= AR5K_TXERR_FILT; } -- 1.7.3.2