sfc: Stop RX refill before flushing RX queues

rx_queue::enabled guards refill, so rename it to reflect that.  Clear
it at the start of the queue teardown process rather than waiting for
the RX queue to be flushed.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index a7818d1..ee9242c 100644
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -248,8 +248,7 @@
 			efx_channel_get_rx_queue(channel);
 
 		efx_rx_flush_packet(channel);
-		if (rx_queue->enabled)
-			efx_fast_push_rx_descriptors(rx_queue);
+		efx_fast_push_rx_descriptors(rx_queue);
 	}
 
 	return spent;
@@ -647,6 +646,12 @@
 	EFX_ASSERT_RESET_SERIALISED(efx);
 	BUG_ON(efx->port_enabled);
 
+	/* Stop RX refill */
+	efx_for_each_channel(channel, efx) {
+		efx_for_each_channel_rx_queue(rx_queue, channel)
+			rx_queue->refill_enabled = false;
+	}
+
 	/* Only perform flush if dma is enabled */
 	if (dev->is_busmaster && efx->state != STATE_RECOVERY) {
 		rc = efx_nic_flush_queues(efx);