From: James Ketrenos Date: Tue, 14 Feb 2006 01:10:51 +0000 (+0800) Subject: [PATCH] ipw2200: stop netdev queue if h/w doesn't have space for new packets X-Git-Tag: v2.6.17-rc1~1186^2^2~22 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f697014af90c1db3c7b299327bf5a9548945b8bf;p=linux-2.6 [PATCH] ipw2200: stop netdev queue if h/w doesn't have space for new packets The patch roll back the change we made to support for the ability to start/stop independent Tx queues within a single net device in order to support 802.11e QoS. We need to be able to indicate to the upper layers that packets of a given priority can not be sent any more without halting transmission of all packets, and without rescheduling high priority packets down to the next priority level. So we return NETDEV_TX_BUSY in this case and rely on the stack would take care of rescheduling... which it apparently does immediately and consumes the CPU. This caused the ksoftirqd kernel thread consuming almost all the CPU... To put the code back to the way it was before we made these changes we put the call netif_queue_stop back in ipw_tx_skb. This effectively disables multiple priority based transmit queues for 802.11e, but given that its broken anyway... Signed-off-by: James Ketrenos Signed-off-by: Zhu Yi Signed-off-by: John W. Linville --- diff --git a/drivers/net/wireless/ipw2200.c b/drivers/net/wireless/ipw2200.c index a7483809d8..4722de13f1 100644 --- a/drivers/net/wireless/ipw2200.c +++ b/drivers/net/wireless/ipw2200.c @@ -9648,11 +9648,6 @@ static int ipw_tx_skb(struct ipw_priv *priv, struct ieee80211_txb *txb, u16 remaining_bytes; int fc; - /* If there isn't room in the queue, we return busy and let the - * network stack requeue the packet for us */ - if (ipw_queue_space(q) < q->high_mark) - return NETDEV_TX_BUSY; - switch (priv->ieee->iw_mode) { case IW_MODE_ADHOC: hdr_len = IEEE80211_3ADDR_LEN; @@ -9818,6 +9813,9 @@ 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) + netif_stop_queue(priv->net_dev); + return NETDEV_TX_OK; drop: