e1000: remove CRC bytes from measured packet length

After removing the hardware CRC stripping which causes problems with
SOL and related issues, we need to compensate for this changed size.
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>

drivers/net/e1000/e1000_main.c

@@ -3673,6 +3673,9 @@ e1000_clean_rx_irq(struct e1000_adapter *adapter,
 
 		length = le16_to_cpu(rx_desc->length);
 
+		/* adjust length to remove Ethernet CRC */
+		length -= 4;
+
 		if (unlikely(!(status & E1000_RXD_STAT_EOP))) {
 			/* All receives must fit into a single buffer */
 			E1000_DBG("%s: Receive packet consumed multiple"
@@ -3877,8 +3880,9 @@ e1000_clean_rx_irq_ps(struct e1000_adapter *adapter,
 			pci_dma_sync_single_for_device(pdev,
 				ps_page_dma->ps_page_dma[0],
 				PAGE_SIZE, PCI_DMA_FROMDEVICE);
+			/* remove the CRC */
+			l1 -= 4;
 			skb_put(skb, l1);
-			length += l1;
 			goto copydone;
 		} /* if */
 		}
@@ -3897,6 +3901,10 @@ e1000_clean_rx_irq_ps(struct e1000_adapter *adapter,
 			skb->truesize += length;
 		}
 
+		/* strip the ethernet crc, problem is we're using pages now so
+		 * this whole operation can get a little cpu intensive */
+		pskb_trim(skb, skb->len - 4);
+
 copydone:
 		e1000_rx_checksum(adapter, staterr,
 				  le16_to_cpu(rx_desc->wb.lower.hi_dword.csum_ip.csum), skb);