From: Sepherosa Ziehau <sephe@dragonflybsd.org>
Date: Thu, 23 Apr 2015 12:21:58 +0000 (+0800)
Subject: emx: Add errata workaround for multiple TX queues
X-Git-Tag: v4.2.0rc~309
X-Git-Url: https://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/57f26b356b7b50aab2bbb0dec9adf665ee6220af

emx: Add errata workaround for multiple TX queues

This makes multiple TX queues work on 82574.

Information-from: Sean Bruno <sbruno@ignoranthack.me>
Tested-with: 82571, 82574, I217
---

diff --git a/share/man/man4/em.4 b/share/man/man4/em.4
index e982cb7923..c303574d4c 100644
--- a/share/man/man4/em.4
+++ b/share/man/man4/em.4
@@ -78,7 +78,7 @@ the
 .Nm emx
 driver will try enabling 2 reception queues
 if there are multiple CPUs on the system.
-For 82571, 82572, I217 and I218
+For 82571, 82572, 82574, I217 and I218
 the
 .Nm emx
 driver could be configured to enable 2 transmission queues.
diff --git a/sys/dev/netif/emx/if_emx.c b/sys/dev/netif/emx/if_emx.c
index aa79ea3381..821c2b8280 100644
--- a/sys/dev/netif/emx/if_emx.c
+++ b/sys/dev/netif/emx/if_emx.c
@@ -661,7 +661,8 @@ emx_attach(device_t dev)
 	if (sc->hw.mac.type == e1000_82571 ||
 	    sc->hw.mac.type == e1000_82572 ||
 	    sc->hw.mac.type == e1000_80003es2lan ||
-	    sc->hw.mac.type == e1000_pch_lpt)
+	    sc->hw.mac.type == e1000_pch_lpt ||
+	    sc->hw.mac.type == e1000_82574)
 		tx_ring_max = EMX_NTX_RING;
 	sc->tx_ring_cnt = device_getenv_int(dev, "txr", emx_txr);
 	sc->tx_ring_cnt = if_ring_count2(sc->tx_ring_cnt, tx_ring_max);
@@ -2283,7 +2284,7 @@ emx_init_tx_ring(struct emx_txdata *tdata)
 static void
 emx_init_tx_unit(struct emx_softc *sc)
 {
-	uint32_t tctl, tarc, tipg = 0;
+	uint32_t tctl, tarc, tipg = 0, txdctl;
 	int i;
 
 	for (i = 0; i < sc->tx_ring_inuse; ++i) {
@@ -2328,6 +2329,14 @@ emx_init_tx_unit(struct emx_softc *sc)
 	E1000_WRITE_REG(&sc->hw, E1000_TIDV, 1);
 	E1000_WRITE_REG(&sc->hw, E1000_TADV, 0);
 
+	/*
+	 * Errata workaround (obtained from Linux).  This is necessary
+	 * to make multiple TX queues work on 82574.
+	 * XXX can't find it in any published errata though.
+	 */
+	txdctl = E1000_READ_REG(&sc->hw, E1000_TXDCTL(0));
+	E1000_WRITE_REG(&sc->hw, E1000_TXDCTL(1), txdctl);
+
 	if (sc->hw.mac.type == e1000_82571 ||
 	    sc->hw.mac.type == e1000_82572) {
 		tarc = E1000_READ_REG(&sc->hw, E1000_TARC(0));