e1000e: do not disable receiver on 82574/82583

Due to a hardware erratum, the receiver on 82574 and 82583 should not be
stopped once it has been started.
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/e1000e/82571.c

@@ -2085,7 +2085,8 @@ struct e1000_info e1000_82574_info = {
 				  | FLAG_HAS_AMT
 				  | FLAG_HAS_CTRLEXT_ON_LOAD,
 	.flags2			  = FLAG2_CHECK_PHY_HANG
-				  | FLAG2_DISABLE_ASPM_L0S,
+				  | FLAG2_DISABLE_ASPM_L0S
+				  | FLAG2_NO_DISABLE_RX,
 	.pba			= 32,
 	.max_hw_frame_size	= DEFAULT_JUMBO,
 	.get_variants		= e1000_get_variants_82571,
@@ -2104,7 +2105,8 @@ struct e1000_info e1000_82583_info = {
 				  | FLAG_HAS_AMT
 				  | FLAG_HAS_JUMBO_FRAMES
 				  | FLAG_HAS_CTRLEXT_ON_LOAD,
-	.flags2			= FLAG2_DISABLE_ASPM_L0S,
+	.flags2			= FLAG2_DISABLE_ASPM_L0S
+				  | FLAG2_NO_DISABLE_RX,
 	.pba			= 32,
 	.max_hw_frame_size	= DEFAULT_JUMBO,
 	.get_variants		= e1000_get_variants_82571,

drivers/net/e1000e/e1000.h

@@ -453,6 +453,7 @@ struct e1000_info {
 #define FLAG2_DISABLE_ASPM_L0S            (1 << 7)
 #define FLAG2_DISABLE_AIM                 (1 << 8)
 #define FLAG2_CHECK_PHY_HANG              (1 << 9)
+#define FLAG2_NO_DISABLE_RX               (1 << 10)
 
 #define E1000_RX_DESC_PS(R, i)	    \
 	(&(((union e1000_rx_desc_packet_split *)((R).desc))[i]))

drivers/net/e1000e/ethtool.c

@@ -1206,7 +1206,8 @@ static int e1000_setup_desc_rings(struct e1000_adapter *adapter)
 	rx_ring->next_to_clean = 0;
 
 	rctl = er32(RCTL);
-	ew32(RCTL, rctl & ~E1000_RCTL_EN);
+	if (!(adapter->flags2 & FLAG2_NO_DISABLE_RX))
+		ew32(RCTL, rctl & ~E1000_RCTL_EN);
 	ew32(RDBAL, ((u64) rx_ring->dma & 0xFFFFFFFF));
 	ew32(RDBAH, ((u64) rx_ring->dma >> 32));
 	ew32(RDLEN, rx_ring->size);

drivers/net/e1000e/netdev.c

@@ -2915,7 +2915,8 @@ static void e1000_configure_rx(struct e1000_adapter *adapter)
 
 	/* disable receives while setting up the descriptors */
 	rctl = er32(RCTL);
-	ew32(RCTL, rctl & ~E1000_RCTL_EN);
+	if (!(adapter->flags2 & FLAG2_NO_DISABLE_RX))
+		ew32(RCTL, rctl & ~E1000_RCTL_EN);
 	e1e_flush();
 	usleep_range(10000, 20000);
 
@@ -3394,7 +3395,8 @@ void e1000e_down(struct e1000_adapter *adapter)
 
 	/* disable receives in the hardware */
 	rctl = er32(RCTL);
-	ew32(RCTL, rctl & ~E1000_RCTL_EN);
+	if (!(adapter->flags2 & FLAG2_NO_DISABLE_RX))
+		ew32(RCTL, rctl & ~E1000_RCTL_EN);
 	/* flush and sleep below */
 
 	netif_stop_queue(netdev);
@@ -3403,6 +3405,7 @@ void e1000e_down(struct e1000_adapter *adapter)
 	tctl = er32(TCTL);
 	tctl &= ~E1000_TCTL_EN;
 	ew32(TCTL, tctl);
+
 	/* flush both disables and wait for them to finish */
 	e1e_flush();
 	usleep_range(10000, 20000);