svn commit: r220079 - stable/7/sys/dev/dc

[Pyun YongHyeon]

Author: yongari
Date: Sun Mar 27 23:14:02 2011
New Revision: 220079
URL: http://svn.freebsd.org/changeset/base/220079

Log:
  MFC r219407:
    Rearrange dc_tx_underrun() a bit to correctly set TX FIFO threshold
    value. Controllers that always require "store and forward" mode(
    Davicom and PNIC 82C168) have no way to recover from TX underrun
    except completely reinitializing hardware. Previously only Davicom
    was reinitialized and the TX FIFO threshold was changed not to use
    "store and forward" mode after reinitialization since the default
    FIFO threshold value was 0. This effectively disabled Davicom
    controller's "store and forward" mode once it encountered TX
    underruns. In theory, this can cause watchodg timeouts.
  
    Intel 21143 controller requires TX MAC should be idle before
    changing TX FIFO threshold. So driver tried to disable TX MAC and
    checked whether it saw the idle state of TX MAC. Driver should
    perform full hardware reinitialization on failing to enter to idle
    state and it should not touch TX MAC again once it performed full
    reinitialization.
  
    While I'm here remove resetting TX FIFO threshold to 0 when
    interface is put into down state. If driver ever encountered TX
    underrun, it's likely to trigger TX underrun again whenever
    interface is brought to up again. Keeping old/learned TX FIFO
    threshold value shall reduce the chance of seeing TX underrns in
    next run.

Modified:
  stable/7/sys/dev/dc/if_dc.c
Directory Properties:
  stable/7/sys/   (props changed)
  stable/7/sys/cddl/contrib/opensolaris/   (props changed)
  stable/7/sys/contrib/dev/acpica/   (props changed)
  stable/7/sys/contrib/pf/   (props changed)

Modified: stable/7/sys/dev/dc/if_dc.c
==============================================================================
--- stable/7/sys/dev/dc/if_dc.c	Sun Mar 27 23:13:02 2011	(r220078)
+++ stable/7/sys/dev/dc/if_dc.c	Sun Mar 27 23:14:02 2011	(r220079)
@@ -3140,50 +3140,57 @@ dc_tick(void *xsc)
 static void
 dc_tx_underrun(struct dc_softc *sc)
 {
-	uint32_t isr;
-	int i;
+	uint32_t netcfg, isr;
+	int i, reinit;
 
-	if (DC_IS_DAVICOM(sc)) {
-		sc->dc_ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
-		dc_init_locked(sc);
-	}
-
-	if (DC_IS_INTEL(sc)) {
-		/*
-		 * The real 21143 requires that the transmitter be idle
-		 * in order to change the transmit threshold or store
-		 * and forward state.
-		 */
-		DC_CLRBIT(sc, DC_NETCFG, DC_NETCFG_TX_ON);
-
-		for (i = 0; i < DC_TIMEOUT; i++) {
-			isr = CSR_READ_4(sc, DC_ISR);
-			if (isr & DC_ISR_TX_IDLE)
-				break;
-			DELAY(10);
-		}
-		if (i == DC_TIMEOUT) {
-			device_printf(sc->dc_dev,
-			    "%s: failed to force tx to idle state\n",
-			    __func__);
-			sc->dc_ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
-			dc_init_locked(sc);
+	reinit = 0;
+	netcfg = CSR_READ_4(sc, DC_NETCFG);
+	device_printf(sc->dc_dev, "TX underrun -- ");
+	if ((sc->dc_flags & DC_TX_STORENFWD) == 0) {
+		if (sc->dc_txthresh + DC_TXTHRESH_INC > DC_TXTHRESH_MAX) {
+			printf("using store and forward mode\n");
+			netcfg |= DC_NETCFG_STORENFWD;
+		} else {
+			printf("increasing TX threshold\n");
+			sc->dc_txthresh += DC_TXTHRESH_INC;
+			netcfg &= ~DC_NETCFG_TX_THRESH;
+			netcfg |= sc->dc_txthresh;
+		}
+
+		if (DC_IS_INTEL(sc)) {
+			/*
+			 * The real 21143 requires that the transmitter be idle
+			 * in order to change the transmit threshold or store
+			 * and forward state.
+			 */
+			CSR_WRITE_4(sc, DC_NETCFG, netcfg & ~DC_NETCFG_TX_ON);
+
+			for (i = 0; i < DC_TIMEOUT; i++) {
+				isr = CSR_READ_4(sc, DC_ISR);
+				if (isr & DC_ISR_TX_IDLE)
+					break;
+				DELAY(10);
+			}
+			if (i == DC_TIMEOUT) {
+				device_printf(sc->dc_dev,
+				    "%s: failed to force tx to idle state\n",
+				    __func__);
+				reinit++;
+			}
 		}
+	} else {
+		printf("resetting\n");
+		reinit++;
 	}
 
-	device_printf(sc->dc_dev, "TX underrun -- ");
-	sc->dc_txthresh += DC_TXTHRESH_INC;
-	if (sc->dc_txthresh > DC_TXTHRESH_MAX) {
-		printf("using store and forward mode\n");
-		DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_STORENFWD);
+	if (reinit == 0) {
+		CSR_WRITE_4(sc, DC_NETCFG, netcfg);
+		if (DC_IS_INTEL(sc))
+			CSR_WRITE_4(sc, DC_NETCFG, netcfg | DC_NETCFG_TX_ON);
 	} else {
-		printf("increasing TX threshold\n");
-		DC_CLRBIT(sc, DC_NETCFG, DC_NETCFG_TX_THRESH);
-		DC_SETBIT(sc, DC_NETCFG, sc->dc_txthresh);
+		sc->dc_ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
+		dc_init_locked(sc);
 	}
-
-	if (DC_IS_INTEL(sc))
-		DC_SETBIT(sc, DC_NETCFG, DC_NETCFG_TX_ON);
 }
 
 #ifdef DEVICE_POLLING
@@ -3821,7 +3828,6 @@ dc_ioctl(struct ifnet *ifp, u_long comma
 				if (need_setfilt)
 					dc_setfilt(sc);
 			} else {
-				sc->dc_txthresh = 0;
 				ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
 				dc_init_locked(sc);
 			}