3 files changed, 126 insertions, 91 deletions

diff --git a/drivers/net/ppp_async.c b/drivers/net/ppp_async.c
index 5de6fedd1d76..6de8399d6dd9 100644
--- a/drivers/net/ppp_async.c
+++ b/drivers/net/ppp_async.c
@@ -157,6 +157,7 @@ ppp_asynctty_open(struct tty_struct *tty)
 {
 	struct asyncppp *ap;
 	int err;
+	int speed;
 
 	if (tty->ops->write == NULL)
 		return -EOPNOTSUPP;
@@ -187,6 +188,8 @@ ppp_asynctty_open(struct tty_struct *tty)
 	ap->chan.private = ap;
 	ap->chan.ops = &async_ops;
 	ap->chan.mtu = PPP_MRU;
+	speed = tty_get_baud_rate(tty);
+	ap->chan.speed = speed;
 	err = ppp_register_channel(&ap->chan);
 	if (err)
 		goto out_free;
diff --git a/drivers/net/ppp_generic.c b/drivers/net/ppp_generic.c
index 42d455578453..8ee91421db12 100644
--- a/drivers/net/ppp_generic.c
+++ b/drivers/net/ppp_generic.c
@@ -167,6 +167,7 @@ struct channel {
 	u8		avail;		/* flag used in multilink stuff */
 	u8		had_frag;	/* >= 1 fragments have been sent */
 	u32		lastseq;	/* MP: last sequence # received */
+	int     speed;		/* speed of the corresponding ppp channel*/
 #endif /* CONFIG_PPP_MULTILINK */
 };
 
@@ -1307,138 +1308,181 @@ ppp_push(struct ppp *ppp)
  */
 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
 {
-	int len, fragsize;
-	int i, bits, hdrlen, mtu;
-	int flen;
-	int navail, nfree;
-	int nbigger;
+	int	len, totlen;
+	int	i, bits, hdrlen, mtu;
+	int	flen;
+	int	navail,	nfree, nzero;
+	int	nbigger;
+	int	totspeed;
+	int	totfree;
 	unsigned char *p, *q;
 	struct list_head *list;
 	struct channel *pch;
 	struct sk_buff *frag;
 	struct ppp_channel *chan;
 
-	nfree = 0;	/* # channels which have no packet already queued */
+	totspeed = 0; /*total bitrate of the bundle*/
+	nfree =	0;	/* # channels which	have no	packet already queued */
 	navail = 0;	/* total # of usable channels (not deregistered) */
+	nzero =	0; /* number of	channels with zero speed associated*/
+	totfree	= 0; /*total # of channels available and
+				  *having no queued packets before
+				  *starting the fragmentation*/
+
 	hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
-	i = 0;
-	list_for_each_entry(pch, &ppp->channels, clist) {
+	i =	0;
+	list_for_each_entry(pch, &ppp->channels, clist)	{
 		navail += pch->avail = (pch->chan != NULL);
-		if (pch->avail) {
+		pch->speed = pch->chan->speed;
+		if (pch->avail)	{
 			if (skb_queue_empty(&pch->file.xq) ||
-			    !pch->had_frag) {
-				pch->avail = 2;
-				++nfree;
-			}
-			if (!pch->had_frag && i < ppp->nxchan)
-				ppp->nxchan = i;
+				!pch->had_frag)	{
+					if (pch->speed == 0)
+						nzero++;
+					else
+						totspeed += pch->speed;
+
+					pch->avail = 2;
+					++nfree;
+					++totfree;
+				}
+			if (!pch->had_frag && i	< ppp->nxchan)
+				ppp->nxchan	= i;
 		}
 		++i;
 	}
-
 	/*
-	 * Don't start sending this packet unless at least half of
-	 * the channels are free.  This gives much better TCP
-	 * performance if we have a lot of channels.
+	 * Don't start sending this	packet unless at least half	of
+	 * the channels	are	free.  This	gives much better TCP
+	 * performance if we have a	lot	of channels.
 	 */
-	if (nfree == 0 || nfree < navail / 2)
-		return 0;	/* can't take now, leave it in xmit_pending */
+	if (nfree == 0 || nfree	< navail / 2)
+		return 0; /* can't take now, leave it in xmit_pending	*/
 
 	/* Do protocol field compression (XXX this should be optional) */
-	p = skb->data;
-	len = skb->len;
+	p =	skb->data;
+	len	= skb->len;
 	if (*p == 0) {
 		++p;
 		--len;
 	}
 
-	/*
-	 * Decide on fragment size.
-	 * We create a fragment for each free channel regardless of
-	 * how small they are (i.e. even 0 length) in order to minimize
-	 * the time that it will take to detect when a channel drops
-	 * a fragment.
-	 */
-	fragsize = len;
-	if (nfree > 1)
-		fragsize = DIV_ROUND_UP(fragsize, nfree);
-	/* nbigger channels get fragsize bytes, the rest get fragsize-1,
-	   except if nbigger==0, then they all get fragsize. */
-	nbigger = len % nfree;
-
-	/* skip to the channel after the one we last used
-	   and start at that one */
+	totlen = len;
+	nbigger	= len %	nfree;
+
+	/* skip	to the channel after the one we	last used
+	   and start at	that one */
 	list = &ppp->channels;
-	for (i = 0; i < ppp->nxchan; ++i) {
+	for	(i = 0;	i <	ppp->nxchan; ++i) {
 		list = list->next;
-		if (list == &ppp->channels) {
-			i = 0;
+		if (list ==	&ppp->channels)	{
+			i =	0;
 			break;
 		}
 	}
 
-	/* create a fragment for each channel */
+	/* create a	fragment for each channel */
 	bits = B;
-	while (nfree > 0 || len > 0) {
+	while (nfree > 0 &&	len	> 0) {
 		list = list->next;
-		if (list == &ppp->channels) {
-			i = 0;
+		if (list ==	&ppp->channels)	{
+			i =	0;
 			continue;
 		}
-		pch = list_entry(list, struct channel, clist);
+		pch	= list_entry(list, struct channel, clist);
 		++i;
 		if (!pch->avail)
 			continue;
 
 		/*
-		 * Skip this channel if it has a fragment pending already and
-		 * we haven't given a fragment to all of the free channels.
+		 * Skip	this channel if	it has a fragment pending already and
+		 * we haven't given	a fragment to all of the free channels.
 		 */
 		if (pch->avail == 1) {
-			if (nfree > 0)
+			if (nfree >	0)
 				continue;
 		} else {
-			--nfree;
 			pch->avail = 1;
 		}
 
 		/* check the channel's mtu and whether it is still attached. */
 		spin_lock_bh(&pch->downl);
 		if (pch->chan == NULL) {
-			/* can't use this channel, it's being deregistered */
+			/* can't use this channel, it's	being deregistered */
+			if (pch->speed == 0)
+				nzero--;
+			else
+				totspeed -=	pch->speed;
+
 			spin_unlock_bh(&pch->downl);
 			pch->avail = 0;
-			if (--navail == 0)
+			totlen = len;
+			totfree--;
+			nfree--;
+			if (--navail ==	0)
 				break;
 			continue;
 		}
 
 		/*
-		 * Create a fragment for this channel of
-		 * min(max(mtu+2-hdrlen, 4), fragsize, len) bytes.
-		 * If mtu+2-hdrlen < 4, that is a ridiculously small
-		 * MTU, so we use mtu = 2 + hdrlen.
+		*if the channel speed is not set divide
+		*the packet	evenly among the free channels;
+		*otherwise divide it according to the speed
+		*of the channel we are going to transmit on
+		*/
+		if (pch->speed == 0) {
+			flen = totlen/nfree	;
+			if (nbigger > 0) {
+				flen++;
+				nbigger--;
+			}
+		} else {
+			flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) /
+				((totspeed*totfree)/pch->speed)) - hdrlen;
+			if (nbigger > 0) {
+				flen += ((totfree - nzero)*pch->speed)/totspeed;
+				nbigger -= ((totfree - nzero)*pch->speed)/
+							totspeed;
+			}
+		}
+		nfree--;
+
+		/*
+		 *check	if we are on the last channel or
+		 *we exceded the lenght	of the data	to
+		 *fragment
+		 */
+		if ((nfree == 0) || (flen > len))
+			flen = len;
+		/*
+		 *it is not worth to tx on slow channels:
+		 *in that case from the resulting flen according to the
+		 *above formula will be equal or less than zero.
+		 *Skip the channel in this case
 		 */
-		if (fragsize > len)
-			fragsize = len;
-		flen = fragsize;
-		mtu = pch->chan->mtu + 2 - hdrlen;
-		if (mtu < 4)
-			mtu = 4;
+		if (flen <=	0) {
+			pch->avail = 2;
+			spin_unlock_bh(&pch->downl);
+			continue;
+		}
+
+		mtu	= pch->chan->mtu + 2 - hdrlen;
+		if (mtu	< 4)
+			mtu	= 4;
 		if (flen > mtu)
 			flen = mtu;
-		if (flen == len && nfree == 0)
-			bits |= E;
-		frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
+		if (flen ==	len)
+			bits |=	E;
+		frag = alloc_skb(flen +	hdrlen + (flen == 0), GFP_ATOMIC);
 		if (!frag)
 			goto noskb;
-		q = skb_put(frag, flen + hdrlen);
+		q =	skb_put(frag, flen + hdrlen);
 
-		/* make the MP header */
+		/* make	the	MP header */
 		q[0] = PPP_MP >> 8;
 		q[1] = PPP_MP;
 		if (ppp->flags & SC_MP_XSHORTSEQ) {
-			q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
+			q[2] = bits	+ ((ppp->nxseq >> 8) & 0xf);
 			q[3] = ppp->nxseq;
 		} else {
 			q[2] = bits;
@@ -1447,43 +1491,28 @@ static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
 			q[5] = ppp->nxseq;
 		}
 
-		/*
-		 * Copy the data in.
-		 * Unfortunately there is a bug in older versions of
-		 * the Linux PPP multilink reconstruction code where it
-		 * drops 0-length fragments.  Therefore we make sure the
-		 * fragment has at least one byte of data.  Any bytes
-		 * we add in this situation will end up as padding on the
-		 * end of the reconstructed packet.
-		 */
-		if (flen == 0)
-			*skb_put(frag, 1) = 0;
-		else
-			memcpy(q + hdrlen, p, flen);
+		memcpy(q + hdrlen, p, flen);
 
 		/* try to send it down the channel */
 		chan = pch->chan;
-		if (!skb_queue_empty(&pch->file.xq) ||
-		    !chan->ops->start_xmit(chan, frag))
+		if (!skb_queue_empty(&pch->file.xq)	||
+			!chan->ops->start_xmit(chan, frag))
 			skb_queue_tail(&pch->file.xq, frag);
-		pch->had_frag = 1;
+		pch->had_frag =	1;
 		p += flen;
-		len -= flen;
+		len	-= flen;
 		++ppp->nxseq;
 		bits = 0;
 		spin_unlock_bh(&pch->downl);
-
-		if (--nbigger == 0 && fragsize > 0)
-			--fragsize;
 	}
-	ppp->nxchan = i;
+	ppp->nxchan	= i;
 
 	return 1;
 
  noskb:
 	spin_unlock_bh(&pch->downl);
 	if (ppp->debug & 1)
-		printk(KERN_ERR "PPP: no memory (fragment)\n");
+		printk(KERN_ERR	"PPP: no memory	(fragment)\n");
 	++ppp->dev->stats.tx_errors;
 	++ppp->nxseq;
 	return 1;	/* abandon the frame */
diff --git a/drivers/net/ppp_synctty.c b/drivers/net/ppp_synctty.c
index 3ea791d16b00..d2fa2db13586 100644
--- a/drivers/net/ppp_synctty.c
+++ b/drivers/net/ppp_synctty.c
@@ -206,6 +206,7 @@ ppp_sync_open(struct tty_struct *tty)
 {
 	struct syncppp *ap;
 	int err;
+	int speed;
 
 	if (tty->ops->write == NULL)
 		return -EOPNOTSUPP;
@@ -234,6 +235,8 @@ ppp_sync_open(struct tty_struct *tty)
 	ap->chan.ops = &sync_ops;
 	ap->chan.mtu = PPP_MRU;
 	ap->chan.hdrlen = 2;	/* for A/C bytes */
+	speed = tty_get_baud_rate(tty);
+	ap->chan.speed = speed;
 	err = ppp_register_channel(&ap->chan);
 	if (err)
 		goto out_free;