Return-path: Received: from mx1.redhat.com ([66.187.233.31]:35610 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752888AbYBKO2o (ORCPT ); Mon, 11 Feb 2008 09:28:44 -0500 Subject: [RFT] ipw2200: fix ucode assertion for RX queue overrun From: Dan Williams To: Sebastian Siewior Cc: "Chatre, Reinette" , "Zhu, Yi" , linux-wireless@vger.kernel.org, ipw2100-devel@lists.sourceforge.net Content-Type: text/plain Date: Mon, 11 Feb 2008 09:27:50 -0500 Message-Id: <1202740070.2806.9.camel@localhost.localdomain> (sfid-20080211_142850_808591_1A705FF6) Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: Restock the RX queue when there are a lot of unused frames so that the RX ring buffer doesn't overrun, causing a ucode assertion. Backport of patch "iwlwifi: fix ucode assertion for RX queue overrun". Signed-off-by: Dan Williams ------------------------------- Sebastian, can you test and ensure that this works for you? Also, can you do some throughput testing to ensure that this patch doesn't cause a throughput regression? Thanks! diff --git a/drivers/net/wireless/ipw2200.c b/drivers/net/wireless/ipw2200.c index 3e6ad7b..a56d9fc 100644 --- a/drivers/net/wireless/ipw2200.c +++ b/drivers/net/wireless/ipw2200.c @@ -3365,7 +3365,6 @@ static void ipw_rx_queue_reset(struct ipw_priv *priv, /* Set us so that we have processed and used all buffers, but have * not restocked the Rx queue with fresh buffers */ rxq->read = rxq->write = 0; - rxq->processed = RX_QUEUE_SIZE - 1; rxq->free_count = 0; spin_unlock_irqrestore(&rxq->lock, flags); } @@ -3607,7 +3606,22 @@ static int ipw_load(struct ipw_priv *priv) * Driver allocates buffers of this size for Rx */ -static inline int ipw_queue_space(const struct clx2_queue *q) +/** + * ipw_rx_queue_space - Return number of free slots available in queue. + */ +static int ipw_rx_queue_space(const struct ipw_rx_queue *q) +{ + int s = q->read - q->write; + if (s <= 0) + s += RX_QUEUE_SIZE; + /* keep some buffer to not confuse full and empty queue */ + s -= 2; + if (s < 0) + s = 0; + return s; +} + +static inline int ipw_tx_queue_space(const struct clx2_queue *q) { int s = q->last_used - q->first_empty; if (s <= 0) @@ -4947,7 +4961,7 @@ static int ipw_queue_tx_reclaim(struct ipw_priv *priv, priv->tx_packets++; } done: - if ((ipw_queue_space(q) > q->low_mark) && + if ((ipw_tx_queue_space(q) > q->low_mark) && (qindex >= 0) && (priv->status & STATUS_ASSOCIATED) && netif_running(priv->net_dev)) netif_wake_queue(priv->net_dev); @@ -4965,7 +4979,7 @@ static int ipw_queue_tx_hcmd(struct ipw_priv *priv, int hcmd, void *buf, struct clx2_queue *q = &txq->q; struct tfd_frame *tfd; - if (ipw_queue_space(q) < (sync ? 1 : 2)) { + if (ipw_tx_queue_space(q) < (sync ? 1 : 2)) { IPW_ERROR("No space for Tx\n"); return -EBUSY; } @@ -5070,7 +5084,7 @@ static void ipw_rx_queue_restock(struct ipw_priv *priv) spin_lock_irqsave(&rxq->lock, flags); write = rxq->write; - while ((rxq->write != rxq->processed) && (rxq->free_count)) { + while ((ipw_rx_queue_space(rxq) > 0) && (rxq->free_count)) { element = rxq->rx_free.next; rxb = list_entry(element, struct ipw_rx_mem_buffer, list); list_del(element); @@ -5187,7 +5201,6 @@ static struct ipw_rx_queue *ipw_rx_queue_alloc(struct ipw_priv *priv) /* Set us so that we have processed and used all buffers, but have * not restocked the Rx queue with fresh buffers */ rxq->read = rxq->write = 0; - rxq->processed = RX_QUEUE_SIZE - 1; rxq->free_count = 0; return rxq; @@ -8223,13 +8236,17 @@ static void ipw_rx(struct ipw_priv *priv) struct ieee80211_hdr_4addr *header; u32 r, w, i; u8 network_packet; + u8 fill_rx = 0; DECLARE_MAC_BUF(mac); DECLARE_MAC_BUF(mac2); DECLARE_MAC_BUF(mac3); r = ipw_read32(priv, IPW_RX_READ_INDEX); w = ipw_read32(priv, IPW_RX_WRITE_INDEX); - i = (priv->rxq->processed + 1) % RX_QUEUE_SIZE; + i = priv->rxq->read; + + if (ipw_rx_queue_space (priv->rxq) > (RX_QUEUE_SIZE / 2)) + fill_rx = 1; while (i != r) { rxb = priv->rxq->queue[i]; @@ -8404,11 +8421,17 @@ static void ipw_rx(struct ipw_priv *priv) list_add_tail(&rxb->list, &priv->rxq->rx_used); i = (i + 1) % RX_QUEUE_SIZE; + + /* If there are a lot of unsued frames, restock the Rx queue + * so the ucode won't assert */ + if (fill_rx) { + priv->rxq->read = i; + ipw_rx_queue_replenish(priv); + } } /* Backtrack one entry */ - priv->rxq->processed = (i ? i : RX_QUEUE_SIZE) - 1; - + priv->rxq->read = i; ipw_rx_queue_restock(priv); } @@ -10336,7 +10359,7 @@ static int ipw_tx_skb(struct ipw_priv *priv, struct ieee80211_txb *txb, q->first_empty = ipw_queue_inc_wrap(q->first_empty, q->n_bd); ipw_write32(priv, q->reg_w, q->first_empty); - if (ipw_queue_space(q) < q->high_mark) + if (ipw_tx_queue_space(q) < q->high_mark) netif_stop_queue(priv->net_dev); return NETDEV_TX_OK; @@ -10357,7 +10380,7 @@ static int ipw_net_is_queue_full(struct net_device *dev, int pri) struct clx2_tx_queue *txq = &priv->txq[0]; #endif /* CONFIG_IPW2200_QOS */ - if (ipw_queue_space(&txq->q) < txq->q.high_mark) + if (ipw_tx_queue_space(&txq->q) < txq->q.high_mark) return 1; return 0;