atl1e: drop pci-msi support because of packet corruption

Usage of pci-msi results in corrupted dma packet transfers to the host.
Reported-by: rebelyouth <rebelyouth.hacklab@gmail.com>
Cc: Huang, Xiong <xiong@qca.qualcomm.com>
Tested-by: Christian Sünkenberg <christian.suenkenberg@student.kit.edu>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/atheros/atl1e/atl1e.h

@@ -438,7 +438,6 @@ struct atl1e_adapter {
 	struct atl1e_hw        hw;
 	struct atl1e_hw_stats  hw_stats;
 
-	bool have_msi;
 	u32 wol;
 	u16 link_speed;
 	u16 link_duplex;

drivers/net/ethernet/atheros/atl1e/atl1e_main.c

@@ -1849,34 +1849,19 @@ static void atl1e_free_irq(struct atl1e_adapter *adapter)
 	struct net_device *netdev = adapter->netdev;
 
 	free_irq(adapter->pdev->irq, netdev);
-
-	if (adapter->have_msi)
-		pci_disable_msi(adapter->pdev);
 }
 
 static int atl1e_request_irq(struct atl1e_adapter *adapter)
 {
 	struct pci_dev    *pdev   = adapter->pdev;
 	struct net_device *netdev = adapter->netdev;
-	int flags = 0;
 	int err = 0;
 
-	adapter->have_msi = true;
-	err = pci_enable_msi(pdev);
-	if (err) {
-		netdev_dbg(netdev,
-			   "Unable to allocate MSI interrupt Error: %d\n", err);
-		adapter->have_msi = false;
-	}
-
-	if (!adapter->have_msi)
-		flags |= IRQF_SHARED;
-	err = request_irq(pdev->irq, atl1e_intr, flags, netdev->name, netdev);
+	err = request_irq(pdev->irq, atl1e_intr, IRQF_SHARED, netdev->name,
+			  netdev);
 	if (err) {
 		netdev_dbg(adapter->netdev,
 			   "Unable to allocate interrupt Error: %d\n", err);
-		if (adapter->have_msi)
-			pci_disable_msi(pdev);
 		return err;
 	}
 	netdev_dbg(netdev, "atl1e_request_irq OK\n");