commit 4b0d29dcfca9eafbf6e940862ab022df3ef2dd6f
author Ben Hutchings <bhutchings@solarflare.com> Sun Nov 29 03:42:18 2009 +0000
committer David S. Miller <davem@davemloft.net> Sun Nov 29 16:46:26 2009 -0800
tree 13af38825d9c0f290f6486f2ae38dc8c55061723
parent 674979d33566ab7e524e25fdc227923e27a3fb78

sfc: Turn pause frame generation on and off at the MAC, not the RX FIFO

Pause frame generation is gated by both RX_XOFF_MAC_EN and an enable
bit in each MAC.  RX_XOFF_MAC_EN bit always reads back as 0 so we need
to set it correctly every time we modify RX_CFG_REG.  Simplify this by
always setting it to 1 and only changing the enable bits in the MACs.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/sfc/falcon.c

diff --git a/drivers/net/sfc/falcon.c b/drivers/net/sfc/falcon.c
index 08f540f..040f553 100644
--- a/drivers/net/sfc/falcon.c
+++ b/drivers/net/sfc/falcon.c
@@ -1939,7 +1939,6 @@
 	struct efx_link_state *link_state = &efx->link_state;
 	efx_oword_t reg;
 	int link_speed;
-	bool tx_fc;
 
 	switch (link_state->speed) {
 	case 10000: link_speed = 3; break;
@@ -1969,13 +1968,10 @@
 	/* Restore the multicast hash registers. */
 	falcon_push_multicast_hash(efx);
 
-	/* Transmission of pause frames when RX crosses the threshold is
-	 * covered by RX_XOFF_MAC_EN and XM_TX_CFG_REG:XM_FCNTL.
-	 * Action on receipt of pause frames is controller by XM_DIS_FCNTL */
-	tx_fc = !!(efx->link_state.fc & EFX_FC_TX);
 	efx_reado(efx, &reg, FR_AZ_RX_CFG);
-	EFX_SET_OWORD_FIELD(reg, FRF_AZ_RX_XOFF_MAC_EN, tx_fc);
-
+	/* Enable XOFF signal from RX FIFO (we enabled it during NIC
+	 * initialisation but it may read back as 0) */
+	EFX_SET_OWORD_FIELD(reg, FRF_AZ_RX_XOFF_MAC_EN, 1);
 	/* Unisolate the MAC -> RX */
 	if (efx_nic_rev(efx) >= EFX_REV_FALCON_B0)
 		EFX_SET_OWORD_FIELD(reg, FRF_BZ_RX_INGR_EN, 1);
@@ -3000,6 +2996,9 @@
 		EFX_SET_OWORD_FIELD(reg, FRF_BZ_RX_XOFF_TX_TH, ctrl_xoff_thr);
 		EFX_SET_OWORD_FIELD(reg, FRF_BZ_RX_INGR_EN, 1);
 	}
+	/* Always enable XOFF signal from RX FIFO.  We enable
+	 * or disable transmission of pause frames at the MAC. */
+	EFX_SET_OWORD_FIELD(reg, FRF_AZ_RX_XOFF_MAC_EN, 1);
 	efx_writeo(efx, &reg, FR_AZ_RX_CFG);
 }