madwifi: nuke some totally wrong code which was causing performance issues

SVN-Revision: 10270

package/madwifi/patches/319-no_queue_stop.patch

@@ -0,0 +1,118 @@
+Index: madwifi-dfs-r3252/ath/if_ath.c
+===================================================================
+--- madwifi-dfs-r3252.orig/ath/if_ath.c	2008-01-26 06:36:36.889082972 +0100
++++ madwifi-dfs-r3252/ath/if_ath.c	2008-01-26 06:41:35.670109540 +0100
+@@ -3082,46 +3082,44 @@
+ {
+ 	struct ath_buf* bf = NULL;
+ 	ATH_TXBUF_LOCK_ASSERT(sc);
++
+ 	/* Reserve at least ATH_TXBUF_MGT_RESERVED buffers for management frames */
+-	if (ath_get_buffers_available() <= ATH_TXBUF_MGT_RESERVED) {
++	if (!for_management && (ath_get_buffers_available() <= ATH_TXBUF_MGT_RESERVED)) {
+ 		/* Stop the queue, we are full */
+ 		DPRINTF(sc, ATH_DEBUG_XMIT, "%s: stopping queuing of additional "
+ 					    "frames.  Insufficient free "
+ 					    "buffers.\n", __func__);
+ 		sc->sc_stats.ast_tx_qstop++;
+-		netif_stop_queue(sc->sc_dev);
+-		sc->sc_devstopped = 1;
+ 		ATH_SCHEDULE_TQUEUE(&sc->sc_txtq, NULL);
++		return NULL;
+ 	}
+ 
+ 	/* Only let us go further if management frame, or there are enough */
+-	if (for_management || (ath_get_buffers_available() > ATH_TXBUF_MGT_RESERVED)) {
+-		bf = STAILQ_FIRST(&sc->sc_txbuf);
+-		if (bf) {
+-			STAILQ_REMOVE_HEAD(&sc->sc_txbuf, bf_list);
+-			/* This should be redundant, unless someone illegally 
+-			 * accessed the buffer after returning it. */
++	bf = STAILQ_FIRST(&sc->sc_txbuf);
++	if (bf) {
++		STAILQ_REMOVE_HEAD(&sc->sc_txbuf, bf_list);
++		/* This should be redundant, unless someone illegally 
++		 * accessed the buffer after returning it. */
+ #ifdef IEEE80211_DEBUG_REFCNT
+-			cleanup_ath_buf_debug(sc, bf, BUS_DMA_TODEVICE, func, line);
++		cleanup_ath_buf_debug(sc, bf, BUS_DMA_TODEVICE, func, line);
+ #else
+-			cleanup_ath_buf(sc, bf, BUS_DMA_TODEVICE);
++		cleanup_ath_buf(sc, bf, BUS_DMA_TODEVICE);
+ #endif
+-			atomic_inc(&ath_buf_counter);
++		atomic_inc(&ath_buf_counter);
+ #ifdef IEEE80211_DEBUG_REFCNT
+-			DPRINTF(sc, ATH_DEBUG_TXBUF, 
+-				"[TXBUF=%03d/%03d] %s:%d -> %s:%d took txbuf %p.\n", 
+-				ath_get_buffer_count(), ATH_TXBUF,
+-				func, line, __func__, __LINE__,
+-				bf);
++		DPRINTF(sc, ATH_DEBUG_TXBUF, 
++			"[TXBUF=%03d/%03d] %s:%d -> %s:%d took txbuf %p.\n", 
++			ath_get_buffer_count(), ATH_TXBUF,
++			func, line, __func__, __LINE__,
++			bf);
+ #endif
+-		}
+-		else {
+-			DPRINTF(sc, ATH_DEBUG_ANY, 
+-				"%s: discard %s, no xmit buffers available.\n", 
+-				__func__,
+-				for_management ? "management frame" : "frame");
+-			sc->sc_stats.ast_tx_nobuf++;
+-		}
++	}
++	else {
++		DPRINTF(sc, ATH_DEBUG_ANY, 
++			"%s: discard %s, no xmit buffers available.\n", 
++			__func__,
++			for_management ? "management frame" : "frame");
++		sc->sc_stats.ast_tx_nobuf++;
+ 	}
+ 
+ 	return bf;
+@@ -3503,9 +3501,6 @@
+ 	/* Pass control of the skb to the caller (i.e., resources are their 
+ 	 * problem). */
+ 	if (requeue) {
+-		/* queue is full, let the kernel backlog the skb */
+-		netif_stop_queue(dev);
+-		sc->sc_devstopped = 1;
+ 		/* Stop tracking again we are giving it back*/
+ 		ieee80211_skb_untrack(skb);
+ 		return NETDEV_TX_BUSY;
+@@ -12871,21 +12866,6 @@
+ 		ath_get_buffer_count(), ATH_TXBUF,
+ 		func, line, __func__, __LINE__, bfaddr);
+ #endif /* #ifdef IEEE80211_DEBUG_REFCNT */
+-	if (sc->sc_devstopped) {
+-		++sc->sc_reapcount;
+-		if (sc->sc_reapcount > ATH_TXBUF_FREE_THRESHOLD) {
+-			if (!ath_radio_silence_required_for_dfs(sc)) {
+-				netif_start_queue(sc->sc_dev);
+-				DPRINTF(sc, ATH_DEBUG_ANY,
+-				    "%s: restarting queue.\n",
+-				    __func__);
+-			}
+-			sc->sc_reapcount = 0;
+-			sc->sc_devstopped = 0;
+-		}
+-		else if (!ath_radio_silence_required_for_dfs(sc))
+-			ATH_SCHEDULE_TQUEUE(&sc->sc_txtq, NULL);
+-	}
+ 
+ 	*bf = NULL;
+ }
+Index: madwifi-dfs-r3252/ath/if_athvar.h
+===================================================================
+--- madwifi-dfs-r3252.orig/ath/if_athvar.h	2008-01-26 06:41:42.206482027 +0100
++++ madwifi-dfs-r3252/ath/if_athvar.h	2008-01-26 06:41:46.646735062 +0100
+@@ -667,7 +667,6 @@
+ 	unsigned int	sc_xrgrppoll:1;		/* xr group polls are active */
+ 	unsigned int	sc_syncbeacon:1;	/* sync/resync beacon timers */
+ 	unsigned int	sc_hasclrkey:1;		/* CLR key supported */
+-	unsigned int	sc_devstopped:1;	/* stopped due to of no tx bufs */
+ 	unsigned int	sc_stagbeacons:1;	/* use staggered beacons */
+ 	unsigned int	sc_dfswait:1;		/* waiting on channel for radar detect */
+ 	unsigned int	sc_ackrate:1;		/* send acks at high bitrate */