sfc: Simplify PHY polling

Falcon can generate events for LASI interrupts from the PHY, but in
practice we have never implemented this in reference designs.  Instead
we have polled, inserted the appropriate events, and then handled the
events later.  This is a waste of time and code.

Instead, make PHY poll functions update the link state synchronously
and report whether it changed.  We can still make use of the LASI
registers as a shortcut on the SFT9001.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/sfc/efx.c b/drivers/net/sfc/efx.c
index 1009d1e..b5a7e91 100644
--- a/drivers/net/sfc/efx.c
+++ b/drivers/net/sfc/efx.c
@@ -583,7 +583,7 @@
  * netif_carrier_on/off) of the link status, and also maintains the
  * link status's stop on the port's TX queue.
  */
-static void efx_link_status_changed(struct efx_nic *efx)
+void efx_link_status_changed(struct efx_nic *efx)
 {
 	struct efx_link_state *link_state = &efx->link_state;
 
@@ -675,19 +675,6 @@
 	mutex_unlock(&efx->mac_lock);
 }
 
-/* Asynchronous efx_reconfigure_port work item. To speed up efx_flush_all()
- * we don't efx_reconfigure_port() if the port is disabled. Care is taken
- * in efx_stop_all() and efx_start_port() to prevent PHY events being lost */
-static void efx_phy_work(struct work_struct *data)
-{
-	struct efx_nic *efx = container_of(data, struct efx_nic, phy_work);
-
-	mutex_lock(&efx->mac_lock);
-	if (efx->port_enabled)
-		__efx_reconfigure_port(efx);
-	mutex_unlock(&efx->mac_lock);
-}
-
 /* Asynchronous work item for changing MAC promiscuity and multicast
  * hash.  Avoid a drain/rx_ingress enable by reconfiguring the current
  * MAC directly. */
@@ -768,9 +755,6 @@
 	return rc;
 }
 
-/* Allow efx_reconfigure_port() to be scheduled, and close the window
- * between efx_stop_port and efx_flush_all whereby a previously scheduled
- * efx_phy_work()/efx_mac_work() may have been cancelled */
 static void efx_start_port(struct efx_nic *efx)
 {
 	EFX_LOG(efx, "start port\n");
@@ -787,10 +771,7 @@
 	mutex_unlock(&efx->mac_lock);
 }
 
-/* Prevent efx_phy_work, efx_mac_work, and efx_monitor() from executing,
- * and efx_set_multicast_list() from scheduling efx_phy_work. efx_phy_work
- * and efx_mac_work may still be scheduled via NAPI processing until
- * efx_flush_all() is called */
+/* Prevent efx_mac_work() and efx_monitor() from working */
 static void efx_stop_port(struct efx_nic *efx)
 {
 	EFX_LOG(efx, "stop port\n");
@@ -1188,8 +1169,6 @@
 
 	/* Stop scheduled port reconfigurations */
 	cancel_work_sync(&efx->mac_work);
-	cancel_work_sync(&efx->phy_work);
-
 }
 
 /* Quiesce hardware and software without bringing the link down.
@@ -1227,7 +1206,7 @@
 	 * window to loose phy events */
 	efx_stop_port(efx);
 
-	/* Flush efx_phy_work, efx_mac_work, refill_workqueue, monitor_work */
+	/* Flush efx_mac_work(), refill_workqueue, monitor_work */
 	efx_flush_all(efx);
 
 	/* Isolate the MAC from the TX and RX engines, so that queue
@@ -1907,6 +1886,10 @@
 void efx_port_dummy_op_set_id_led(struct efx_nic *efx, enum efx_led_mode mode)
 {
 }
+bool efx_port_dummy_op_poll(struct efx_nic *efx)
+{
+	return false;
+}
 
 static struct efx_mac_operations efx_dummy_mac_operations = {
 	.reconfigure	= efx_port_dummy_op_void,
@@ -1915,9 +1898,8 @@
 static struct efx_phy_operations efx_dummy_phy_operations = {
 	.init		 = efx_port_dummy_op_int,
 	.reconfigure	 = efx_port_dummy_op_void,
-	.poll		 = efx_port_dummy_op_void,
+	.poll		 = efx_port_dummy_op_poll,
 	.fini		 = efx_port_dummy_op_void,
-	.clear_interrupt = efx_port_dummy_op_void,
 };
 
 /**************************************************************************
@@ -1957,7 +1939,6 @@
 	efx->mac_op = &efx_dummy_mac_operations;
 	efx->phy_op = &efx_dummy_phy_operations;
 	efx->mdio.dev = net_dev;
-	INIT_WORK(&efx->phy_work, efx_phy_work);
 	INIT_WORK(&efx->mac_work, efx_mac_work);
 	atomic_set(&efx->netif_stop_count, 1);