bnx2x: recognize fan failure

If fan failure is detected, MCP prevents PCI I/O registers from being
mapped to the bar, causing a fatal error as driver is unaware.

This patch recognizes such an event occurred and gracefully terminates
the probe process.
Signed-off-by: Yaniv Rosner <yaniv.rosner@broadcom.com>
Signed-off-by: Yuval Mintz <yuvalmin@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

@@ -11570,6 +11570,14 @@ static int __devinit bnx2x_init_dev(struct pci_dev *pdev,
 		goto err_out_disable;
 	}
 
+	pci_read_config_dword(pdev, PCICFG_REVISION_ID_OFFSET, &pci_cfg_dword);
+	if ((pci_cfg_dword & PCICFG_REVESION_ID_MASK) ==
+	    PCICFG_REVESION_ID_ERROR_VAL) {
+		pr_err("PCI device error, probably due to fan failure, aborting\n");
+		rc = -ENODEV;
+		goto err_out_disable;
+	}
+
 	if (atomic_read(&pdev->enable_cnt) == 1) {
 		rc = pci_request_regions(pdev, DRV_MODULE_NAME);
 		if (rc) {

drivers/net/ethernet/broadcom/bnx2x/bnx2x_reg.h

@@ -6160,7 +6160,9 @@
 #define PCICFG_COMMAND_INT_DISABLE		(1<<10)
 #define PCICFG_COMMAND_RESERVED 		(0x1f<<11)
 #define PCICFG_STATUS_OFFSET				0x06
-#define PCICFG_REVESION_ID_OFFSET			0x08
+#define PCICFG_REVISION_ID_OFFSET			0x08
+#define PCICFG_REVESION_ID_MASK			0xff
+#define PCICFG_REVESION_ID_ERROR_VAL		0xff
 #define PCICFG_CACHE_LINE_SIZE				0x0c
 #define PCICFG_LATENCY_TIMER				0x0d
 #define PCICFG_BAR_1_LOW				0x10