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>

diff --git a/drivers/net/sfc/falcon.c b/drivers/net/sfc/falcon.c
index 08f540f..040f553 100644 (file)
--- a/drivers/net/sfc/falcon.c
+++ b/drivers/net/sfc/falcon.c
@@ -1939,7 +1939,6 @@ void falcon_reconfigure_mac_wrapper(struct efx_nic *efx)
        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 @@ void falcon_reconfigure_mac_wrapper(struct efx_nic *efx)
        /* 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 @@ static void falcon_init_rx_cfg(struct efx_nic *efx)
                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);
 }
 

diff --git a/drivers/net/sfc/falcon_xmac.c b/drivers/net/sfc/falcon_xmac.c
index 1523efd..60dc097 100644 (file)
--- a/drivers/net/sfc/falcon_xmac.c
+++ b/drivers/net/sfc/falcon_xmac.c
@@ -148,6 +148,7 @@ static void falcon_reconfigure_xmac_core(struct efx_nic *efx)
        unsigned int max_frame_len;
        efx_oword_t reg;
        bool rx_fc = !!(efx->link_state.fc & EFX_FC_RX);
+       bool tx_fc = !!(efx->link_state.fc & EFX_FC_TX);
 
        /* Configure MAC  - cut-thru mode is hard wired on */
        EFX_POPULATE_OWORD_3(reg,
@@ -162,7 +163,7 @@ static void falcon_reconfigure_xmac_core(struct efx_nic *efx)
                             FRF_AB_XM_TX_PRMBL, 1,
                             FRF_AB_XM_AUTO_PAD, 1,
                             FRF_AB_XM_TXCRC, 1,
-                            FRF_AB_XM_FCNTL, 1,
+                            FRF_AB_XM_FCNTL, tx_fc,
                             FRF_AB_XM_IPG, 0x3);
        efx_writeo(efx, &reg, FR_AB_XM_TX_CFG);