From 4dfae5a5e8b316e524ea391625891864eb6d6cdb Mon Sep 17 00:00:00 2001
From: Luigi Rizzo <luigi@FreeBSD.org>
Date: Sun, 30 Jun 2002 21:59:08 +0000
Subject: [PATCH] Make sure that if_timer does not get reset if there are
 packets still queued for transmission. This should solve the problem of the
 device stalling on transmissions if some link event prevents transmission.

There are other drivers which have the same problem and need to be
fixed in the same way.

MFC after: 3 days
---
 sys/pci/if_sis.c    | 28 ++++++++++------------------
 sys/pci/if_sisreg.h |  2 +-
 2 files changed, 11 insertions(+), 19 deletions(-)

diff --git a/sys/pci/if_sis.c b/sys/pci/if_sis.c
index 22a2163f7c9..380195747b8 100644
--- a/sys/pci/if_sis.c
+++ b/sys/pci/if_sis.c
@@ -1393,31 +1393,24 @@ void sis_rxeoc(sc)
 static void sis_txeof(sc)
 	struct sis_softc	*sc;
 {
-	struct sis_desc		*cur_tx = NULL;
 	struct ifnet		*ifp;
 	u_int32_t		idx;
 
 	ifp = &sc->arpcom.ac_if;
 
-	/* Clear the timeout timer. */
-	ifp->if_timer = 0;
-
 	/*
 	 * Go through our tx list and free mbufs for those
 	 * frames that have been transmitted.
 	 */
-	idx = sc->sis_cdata.sis_tx_cons;
-	while (idx != sc->sis_cdata.sis_tx_prod) {
-		cur_tx = &sc->sis_ldata.sis_tx_list[idx];
+	for (idx = sc->sis_cdata.sis_tx_cons; sc->sis_cdata.sis_tx_cnt > 0;
+	    sc->sis_cdata.sis_tx_cnt--, SIS_INC(idx, SIS_TX_LIST_CNT) ) {
+		struct sis_desc *cur_tx = &sc->sis_ldata.sis_tx_list[idx];
 
 		if (SIS_OWNDESC(cur_tx))
 			break;
 
-		if (cur_tx->sis_ctl & SIS_CMDSTS_MORE) {
-			sc->sis_cdata.sis_tx_cnt--;
-			SIS_INC(idx, SIS_TX_LIST_CNT);
+		if (cur_tx->sis_ctl & SIS_CMDSTS_MORE)
 			continue;
-		}
 
 		if (!(cur_tx->sis_ctl & SIS_CMDSTS_PKT_OK)) {
 			ifp->if_oerrors++;
@@ -1437,16 +1430,15 @@ static void sis_txeof(sc)
 			bus_dmamap_unload(sc->sis_tag, cur_tx->sis_map);
 			bus_dmamap_destroy(sc->sis_tag, cur_tx->sis_map);
 		}
-
-		sc->sis_cdata.sis_tx_cnt--;
-		SIS_INC(idx, SIS_TX_LIST_CNT);
-		ifp->if_timer = 0;
 	}
 
-	sc->sis_cdata.sis_tx_cons = idx;
-
-	if (cur_tx != NULL)
+	if (idx != sc->sis_cdata.sis_tx_cons) {
+		/* we freed up some buffers */
+		sc->sis_cdata.sis_tx_cons = idx;
 		ifp->if_flags &= ~IFF_OACTIVE;
+	}
+
+	ifp->if_timer = (sc->sis_cdata.sis_tx_cnt == 0) ? 0 : 5;
 
 	return;
 }
diff --git a/sys/pci/if_sisreg.h b/sys/pci/if_sisreg.h
index 8244f2a2f15..2e2ee19a5bb 100644
--- a/sys/pci/if_sisreg.h
+++ b/sys/pci/if_sisreg.h
@@ -309,7 +309,7 @@ struct sis_desc {
 
 #define SIS_LASTDESC(x)		(!((x)->sis_ctl & SIS_CMDSTS_MORE)))
 #define SIS_OWNDESC(x)		((x)->sis_ctl & SIS_CMDSTS_OWN)
-#define SIS_INC(x, y)		{ if (++(x) == y) x = 0; }
+#define SIS_INC(x, y)		(x) = ((x) == ((y)-1)) ? 0 : (x)+1
 #define SIS_RXBYTES(x)		(((x)->sis_ctl & SIS_CMDSTS_BUFLEN) - ETHER_CRC_LEN)
 
 #define SIS_RXSTAT_COLL		0x00010000