sfc: Include XGXS in XMAC link status check except in XGMII loopback

The XGXS block may not get a link immediately in XGXS or XAUI loopback
modes, so we still need to check it.  Split falcon_xaui_link_ok() into
falcon_xgxs_link_ok(), which checks only the Falcon XGXS block, and
falcon_xmac_link_ok(), which checks one or both sides of the link as
appropriate.  Also rename falcon_check_xaui_link() to
falcon_xmac_link_ok_retry().

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

drivers/net/sfc/falcon_xmac.c

@@ -111,16 +111,12 @@ static void falcon_mask_status_intr(struct efx_nic *efx, bool enable)
 	efx_writeo(efx, &reg, FR_AB_XM_MGT_INT_MASK);
 }
 
-/* Get status of XAUI link */
-static bool falcon_xaui_link_ok(struct efx_nic *efx)
+static bool falcon_xgxs_link_ok(struct efx_nic *efx)
 {
 	efx_oword_t reg;
 	bool align_done, link_ok = false;
 	int sync_status;
 
-	if (LOOPBACK_INTERNAL(efx))
-		return true;
-
 	/* Read link status */
 	efx_reado(efx, &reg, FR_AB_XX_CORE_STAT);
 
@@ -135,14 +131,24 @@ static bool falcon_xaui_link_ok(struct efx_nic *efx)
 	EFX_SET_OWORD_FIELD(reg, FRF_AB_XX_DISPERR, FFE_AB_XX_STAT_ALL_LANES);
 	efx_writeo(efx, &reg, FR_AB_XX_CORE_STAT);
 
-	/* If the link is up, then check the phy side of the xaui link */
-	if (efx->link_state.up && link_ok)
-		if (efx->mdio.mmds & (1 << MDIO_MMD_PHYXS))
-			link_ok = efx_mdio_phyxgxs_lane_sync(efx);
-
 	return link_ok;
 }
 
+static bool falcon_xmac_link_ok(struct efx_nic *efx)
+{
+	/*
+	 * Check MAC's XGXS link status except when using XGMII loopback
+	 * which bypasses the XGXS block.
+	 * If possible, check PHY's XGXS link status except when using
+	 * MAC loopback.
+	 */
+	return (efx->loopback_mode == LOOPBACK_XGMII ||
+		falcon_xgxs_link_ok(efx)) &&
+		(!(efx->mdio.mmds & (1 << MDIO_MMD_PHYXS)) ||
+		 LOOPBACK_INTERNAL(efx) || 
+		 efx_mdio_phyxgxs_lane_sync(efx));
+}
+
 void falcon_reconfigure_xmac_core(struct efx_nic *efx)
 {
 	unsigned int max_frame_len;
@@ -245,9 +251,9 @@ static void falcon_reconfigure_xgxs_core(struct efx_nic *efx)
 
 
 /* Try to bring up the Falcon side of the Falcon-Phy XAUI link */
-static bool falcon_check_xaui_link_up(struct efx_nic *efx, int tries)
+static bool falcon_xmac_link_ok_retry(struct efx_nic *efx, int tries)
 {
-	bool mac_up = falcon_xaui_link_ok(efx);
+	bool mac_up = falcon_xmac_link_ok(efx);
 
 	if (LOOPBACK_MASK(efx) & LOOPBACKS_EXTERNAL(efx) & LOOPBACKS_WS ||
 	    efx_phy_mode_disabled(efx->phy_mode))
@@ -261,7 +267,7 @@ static bool falcon_check_xaui_link_up(struct efx_nic *efx, int tries)
 		falcon_reset_xaui(efx);
 		udelay(200);
 
-		mac_up = falcon_xaui_link_ok(efx);
+		mac_up = falcon_xmac_link_ok(efx);
 		--tries;
 	}
 
@@ -272,7 +278,7 @@ static bool falcon_check_xaui_link_up(struct efx_nic *efx, int tries)
 
 static bool falcon_xmac_check_fault(struct efx_nic *efx)
 {
-	return !falcon_check_xaui_link_up(efx, 5);
+	return !falcon_xmac_link_ok_retry(efx, 5);
 }
 
 static int falcon_reconfigure_xmac(struct efx_nic *efx)
@@ -284,7 +290,7 @@ static int falcon_reconfigure_xmac(struct efx_nic *efx)
 
 	falcon_reconfigure_mac_wrapper(efx);
 
-	efx->xmac_poll_required = !falcon_check_xaui_link_up(efx, 5);
+	efx->xmac_poll_required = !falcon_xmac_link_ok_retry(efx, 5);
 	falcon_mask_status_intr(efx, true);
 
 	return 0;
@@ -357,7 +363,7 @@ void falcon_poll_xmac(struct efx_nic *efx)
 		return;
 
 	falcon_mask_status_intr(efx, false);
-	efx->xmac_poll_required = !falcon_check_xaui_link_up(efx, 1);
+	efx->xmac_poll_required = !falcon_xmac_link_ok_retry(efx, 1);
 	falcon_mask_status_intr(efx, true);
 }