bnx2x: fix unload previous driver flow when flr-capable

The existing previous driver unload flow is flawed, causing the probe of
functions reaching the 'uncommon fork' in flr-capable devices to fail.

This patch resolves this, as well as fixing the flow for hypervisors which
disable flr capabilities from functions as they pass them as PDA to VMs,
as we cannot base the flow on the pci configuration space.

Signed-off-by: Yuval Mintz <yuvalmin@broadcom.com>
Signed-off-by: Ariel Elior <ariele@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c

@@ -9384,32 +9384,24 @@ static int __devinit bnx2x_prev_mark_path(struct bnx2x *bp)
 	return rc;
 }
 
-static bool __devinit bnx2x_can_flr(struct bnx2x *bp)
-{
-	int pos;
-	u32 cap;
-	struct pci_dev *dev = bp->pdev;
-
-	pos = pci_pcie_cap(dev);
-	if (!pos)
-		return false;
-
-	pci_read_config_dword(dev, pos + PCI_EXP_DEVCAP, &cap);
-	if (!(cap & PCI_EXP_DEVCAP_FLR))
-		return false;
-
-	return true;
-}
-
 static int __devinit bnx2x_do_flr(struct bnx2x *bp)
 {
 	int i, pos;
 	u16 status;
 	struct pci_dev *dev = bp->pdev;
 
-	/* probe the capability first */
-	if (bnx2x_can_flr(bp))
-		return -ENOTTY;
+
+	if (CHIP_IS_E1x(bp)) {
+		BNX2X_DEV_INFO("FLR not supported in E1/E1H\n");
+		return -EINVAL;
+	}
+
+	/* only bootcode REQ_BC_VER_4_INITIATE_FLR and onwards support flr */
+	if (bp->common.bc_ver < REQ_BC_VER_4_INITIATE_FLR) {
+		BNX2X_ERR("FLR not supported by BC_VER: 0x%x\n",
+			  bp->common.bc_ver);
+		return -EINVAL;
+	}
 
 	pos = pci_pcie_cap(dev);
 	if (!pos)
@@ -9429,12 +9421,8 @@ static int __devinit bnx2x_do_flr(struct bnx2x *bp)
 		"transaction is not cleared; proceeding with reset anyway\n");
 
 clear:
-	if (bp->common.bc_ver < REQ_BC_VER_4_INITIATE_FLR) {
-		BNX2X_ERR("FLR not supported by BC_VER: 0x%x\n",
-			  bp->common.bc_ver);
-		return -EINVAL;
-	}
 
+	BNX2X_DEV_INFO("Initiating FLR\n");
 	bnx2x_fw_command(bp, DRV_MSG_CODE_INITIATE_FLR, 0);
 
 	return 0;
@@ -9454,8 +9442,21 @@ static int __devinit bnx2x_prev_unload_uncommon(struct bnx2x *bp)
 	 * the one required, then FLR will be sufficient to clean any residue
 	 * left by previous driver
 	 */
-	if (bnx2x_test_firmware_version(bp, false) && bnx2x_can_flr(bp))
-		return bnx2x_do_flr(bp);
+	rc = bnx2x_test_firmware_version(bp, false);
+
+	if (!rc) {
+		/* fw version is good */
+		BNX2X_DEV_INFO("FW version matches our own. Attempting FLR\n");
+		rc = bnx2x_do_flr(bp);
+	}
+
+	if (!rc) {
+		/* FLR was performed */
+		BNX2X_DEV_INFO("FLR successful\n");
+		return 0;
+	}
+
+	BNX2X_DEV_INFO("Could not FLR\n");
 
 	/* Close the MCP request, return failure*/
 	rc = bnx2x_prev_mcp_done(bp);