qla2xxx: Schedule board_disable only once

There are various callers of qla2x00_check_reg{32,16}_for_disconnect
that may schedule board removal on PCI-disconnect. Test-and-set a
dedicated flag before scheduling board_disable so it is invoked only
once.
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>

drivers/scsi/qla2xxx/qla_def.h

@@ -3402,6 +3402,9 @@ typedef struct scsi_qla_host {
 #define FX00_CRITEMP_RECOVERY	25
 #define FX00_HOST_INFO_RESEND	26
 
+	unsigned long	pci_flags;
+#define PFLG_DISCONNECTED	0	/* PCI device removed */
+
 	uint32_t	device_flags;
 #define SWITCH_FOUND		BIT_0
 #define DFLG_NO_CABLE		BIT_1

drivers/scsi/qla2xxx/qla_isr.c

@@ -117,12 +117,14 @@ qla2x00_check_reg32_for_disconnect(scsi_qla_host_t *vha, uint32_t reg)
 {
 	/* Check for PCI disconnection */
 	if (reg == 0xffffffff) {
-		/*
-		 * Schedule this on the default system workqueue so that all the
-		 * adapter workqueues and the DPC thread can be shutdown
-		 * cleanly.
-		 */
-		schedule_work(&vha->hw->board_disable);
+		if (!test_and_set_bit(PFLG_DISCONNECTED, &vha->pci_flags)) {
+			/*
+			 * Schedule this (only once) on the default system
+			 * workqueue so that all the adapter workqueues and the
+			 * DPC thread can be shutdown cleanly.
+			 */
+			schedule_work(&vha->hw->board_disable);
+		}
 		return true;
 	} else
 		return false;