[ath9k-devel] [PATCH v2 2/2] ath9k: Use GFP_ATOMIC when allocating TX private area

2008-12-02 Thread Sujith
Luis R. Rodriguez wrote:
 @@ -1813,10 +1815,30 @@ int ath_tx_start(struct ath_softc *sc, struct sk_buff 
 *skb,
  
   r = ath_tx_setup_buffer(sc, bf, skb, txctl);
   if (r) {
 - spin_lock_bh(sc-sc_txbuflock);
 + struct ath_txq *txq = NULL;
 + int qnum;
 +
 + qnum = ath_get_hal_qnum(skb_get_queue_mapping(skb), sc);
 + txq = sc-sc_txq[qnum];
 +
   DPRINTF(sc, ATH_DBG_FATAL, TX mem alloc failure\n);
 +
 + /* upon ath_tx_processq() this TX queue will be resumed, we
 +  * guarantee this will happen by knowing beforehand that
 +  * we will at least have to run TX completionon one buffer
 +  * on the queue */
 + spin_lock_bh(txq-axq_lock);
 + if (ath_txq_depth(sc, txq-axq_qnum)  1) {
 + ieee80211_stop_queue(sc-hw,
 + skb_get_queue_mapping(skb));
 + txq-stopped = 1;
 + }
 + spin_unlock_bh(txq-axq_lock);
 +
 + spin_lock_bh(sc-sc_txbuflock);
   list_add_tail(bf-list, sc-sc_txbuf);
   spin_unlock_bh(sc-sc_txbuflock);
 +

The queue is already available, we make sure of that before calling 
ath_tx_start().
And the queue is sent through txctl.txq, you don't have to calculate the queue 
number again.

So, just stopping the queue and moving the buffer back to the free list would 
be enough.

Sujith
___
ath9k-devel mailing list
ath9k-devel@lists.ath9k.org
https://lists.ath9k.org/mailman/listinfo/ath9k-devel


Re: [ath9k-devel] [PATCH v2 2/2] ath9k: Use GFP_ATOMIC when allocating TX private area

2008-12-02 Thread Luis R. Rodriguez
On Tue, Dec 2, 2008 at 7:46 PM, Sujith [EMAIL PROTECTED] wrote:
 Luis R. Rodriguez wrote:
 @@ -1813,10 +1815,30 @@ int ath_tx_start(struct ath_softc *sc, struct 
 sk_buff *skb,

   r = ath_tx_setup_buffer(sc, bf, skb, txctl);
   if (r) {
 - spin_lock_bh(sc-sc_txbuflock);
 + struct ath_txq *txq = NULL;
 + int qnum;
 +
 + qnum = ath_get_hal_qnum(skb_get_queue_mapping(skb), sc);
 + txq = sc-sc_txq[qnum];
 +
   DPRINTF(sc, ATH_DBG_FATAL, TX mem alloc failure\n);
 +
 + /* upon ath_tx_processq() this TX queue will be resumed, we
 +  * guarantee this will happen by knowing beforehand that
 +  * we will at least have to run TX completionon one buffer
 +  * on the queue */
 + spin_lock_bh(txq-axq_lock);
 + if (ath_txq_depth(sc, txq-axq_qnum)  1) {
 + ieee80211_stop_queue(sc-hw,
 + skb_get_queue_mapping(skb));
 + txq-stopped = 1;
 + }
 + spin_unlock_bh(txq-axq_lock);
 +
 + spin_lock_bh(sc-sc_txbuflock);
   list_add_tail(bf-list, sc-sc_txbuf);
   spin_unlock_bh(sc-sc_txbuflock);
 +

 The queue is already available, we make sure of that before calling 
 ath_tx_start().
 And the queue is sent through txctl.txq, you don't have to calculate the 
 queue number again.

 So, just stopping the queue and moving the buffer back to the free list would 
 be enough.

ath_test_get_txq() will not return the queue only if the queue is
getting full. What the check above guarantees is we have at least one
buffer to run through procesq before disabling the TX queue, otherwise
the queue won't be be woken up. Or am I missing something? That is,
say you just have to TX one skb and we hit -ENOMEM on
ath_tx_setup_buffer() and you disable the queue. How will this queue
be awoken if this is true in ath_tx_processq():

list_empty(txq-axq_q)

  Luis
___
ath9k-devel mailing list
ath9k-devel@lists.ath9k.org
https://lists.ath9k.org/mailman/listinfo/ath9k-devel