qla2xxx: Prevent probe and board_disable race

The PCI register read checking introduced in commit fe1b806f4f71
("qla2xxx: Disable adapter when we encounter a PCI disconnect") is
active during driver probe. Hold off scheduling any board removal until
the driver probe has completed. This ensures that the the board_disable
work structure is initialized and more importantly, avoids racing
qla2x00_probe_one.

Signed-off-by: Joe Lawrence <joe.lawrence@stratus.com>
Acked-by: Chad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h
index 1398818..de5a9c4 100644
--- a/drivers/scsi/qla2xxx/qla_def.h
+++ b/drivers/scsi/qla2xxx/qla_def.h
@@ -3405,6 +3405,7 @@
 	unsigned long	pci_flags;
 #define PFLG_DISCONNECTED	0	/* PCI device removed */
 #define PFLG_DRIVER_REMOVING	1	/* PCI driver .remove */
+#define PFLG_DRIVER_PROBING	2	/* PCI driver .probe */
 
 	uint32_t	device_flags;
 #define SWITCH_FOUND		BIT_0
diff --git a/drivers/scsi/qla2xxx/qla_isr.c b/drivers/scsi/qla2xxx/qla_isr.c
index 341c64d..a0992bf 100644
--- a/drivers/scsi/qla2xxx/qla_isr.c
+++ b/drivers/scsi/qla2xxx/qla_isr.c
@@ -118,7 +118,8 @@
 	/* Check for PCI disconnection */
 	if (reg == 0xffffffff) {
 		if (!test_and_set_bit(PFLG_DISCONNECTED, &vha->pci_flags) &&
-		    !test_bit(PFLG_DRIVER_REMOVING, &vha->pci_flags)) {
+		    !test_bit(PFLG_DRIVER_REMOVING, &vha->pci_flags) &&
+		    !test_bit(PFLG_DRIVER_PROBING, &vha->pci_flags)) {
 			/*
 			 * Schedule this (only once) on the default system
 			 * workqueue so that all the adapter workqueues and the
diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 84d4df6..f937859 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -2632,6 +2632,7 @@
 	}
 
 	pci_set_drvdata(pdev, base_vha);
+	set_bit(PFLG_DRIVER_PROBING, &base_vha->pci_flags);
 
 	host = base_vha->host;
 	base_vha->req = req;
@@ -2928,6 +2929,7 @@
 
 	qlt_add_target(ha, base_vha);
 
+	clear_bit(PFLG_DRIVER_PROBING, &base_vha->pci_flags);
 	return 0;
 
 probe_init_failed: