qed: Fix link flap issue due to mismatching EEE capabilities.

Apparently, MFW publishes EEE capabilities even for Fiber-boards that don't
support them, and later since qed internally sets adv_caps it would cause
link-flap avoidance (LFA) to fail when driver would initiate the link.
This in turn delays the link, causing traffic to fail.

Driver has been modified to not to ask MFW for any EEE config if EEE isn't
to be enabled.

Fixes: 645874e5 ("qed: Add support for Energy efficient ethernet.")
Signed-off-by: NSudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: NAriel Elior <ariel.elior@cavium.com>
Signed-off-by: NMichal Kalderon <Michal.Kalderon@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/qlogic/qed/qed_mcp.c

@@ -1308,9 +1308,15 @@ int qed_mcp_set_link(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt, bool b_up)
 	phy_cfg.pause |= (params->pause.forced_tx) ? ETH_PAUSE_TX : 0;
 	phy_cfg.adv_speed = params->speed.advertised_speeds;
 	phy_cfg.loopback_mode = params->loopback_mode;
-	if (p_hwfn->mcp_info->capabilities & FW_MB_PARAM_FEATURE_SUPPORT_EEE) {
-		if (params->eee.enable)
-			phy_cfg.eee_cfg |= EEE_CFG_EEE_ENABLED;
+
+	/* There are MFWs that share this capability regardless of whether
+	 * this is feasible or not. And given that at the very least adv_caps
+	 * would be set internally by qed, we want to make sure LFA would
+	 * still work.
+	 */
+	if ((p_hwfn->mcp_info->capabilities &
+	     FW_MB_PARAM_FEATURE_SUPPORT_EEE) && params->eee.enable) {
+		phy_cfg.eee_cfg |= EEE_CFG_EEE_ENABLED;
 		if (params->eee.tx_lpi_enable)
 			phy_cfg.eee_cfg |= EEE_CFG_TX_LPI;
 		if (params->eee.adv_caps & QED_EEE_1G_ADV)