[PATCH] PPC44x EMAC driver: disable TX status deferral in half-duplex mode

Disable TX status deferral (EMACx_MR[MWSW=001]) in half-duplex mode.
I have two reports when EMAC stops transmitting when connected to a
hub. TX ring debug printouts show complete mess when this happens,
probably hardware collision handling doesn't work quite well in this
mode.

This is relevant only for SoCs with EMAC4 core (440GX, 440SP, 440SPe).
Tested on 440GX.
Signed-off-by: Eugene Surovegin <ebs@ebshome.net>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

drivers/net/ibm_emac/ibm_emac.h

@@ -110,6 +110,7 @@ struct emac_regs {
 #define EMAC_MR1_TFS_2K			0x00080000
 #define EMAC_MR1_TR0_MULT		0x00008000
 #define EMAC_MR1_JPSM			0x00000000
+#define EMAC_MR1_MWSW_001		0x00000000
 #define EMAC_MR1_BASE(opb)		(EMAC_MR1_TFS_2K | EMAC_MR1_TR0_MULT)
 #else
 #define EMAC_MR1_RFS_4K			0x00180000
@@ -130,7 +131,7 @@ struct emac_regs {
 					 (freq) <= 83  ? EMAC_MR1_OBCI_83 : \
 					 (freq) <= 100 ? EMAC_MR1_OBCI_100 : EMAC_MR1_OBCI_100P)
 #define EMAC_MR1_BASE(opb)		(EMAC_MR1_TFS_2K | EMAC_MR1_TR | \
-					 EMAC_MR1_MWSW_001 | EMAC_MR1_OBCI(opb))
+					 EMAC_MR1_OBCI(opb))
 #endif
 
 /* EMACx_TMR0 */

drivers/net/ibm_emac/ibm_emac_core.c

@@ -408,7 +408,7 @@ static int emac_configure(struct ocp_enet_private *dev)
 	/* Mode register */
 	r = EMAC_MR1_BASE(emac_opb_mhz()) | EMAC_MR1_VLE | EMAC_MR1_IST;
 	if (dev->phy.duplex == DUPLEX_FULL)
-		r |= EMAC_MR1_FDE;
+		r |= EMAC_MR1_FDE | EMAC_MR1_MWSW_001;
 	dev->stop_timeout = STOP_TIMEOUT_10;
 	switch (dev->phy.speed) {
 	case SPEED_1000: