scsi: qedf: Wait for stag work during unload

If stag work is already scheduled and unload is called, it can lead to
issues as unload cleans up the work element. Wait for stag work to get
completed before cleanup during unload.

Signed-off-by: Saurav Kashyap <[e-mail]>
Signed-off-by: Nilesh Javali <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Martin K. Petersen <[e-mail]>

drivers/scsi/qedf/qedf.h

···
 #define QEDF_IN_RECOVERY		5
 #define QEDF_DBG_STOP_IO		6
 #define QEDF_PROBING			8
+#define QEDF_STAG_IN_PROGRESS		9
 	unsigned long flags; /* Miscellaneous state flags */
 	int fipvlan_retries;
 	u8 num_queues;

drivers/scsi/qedf/qedf_main.c

···
 	 */
 	if (resp == fc_lport_flogi_resp) {
 		qedf->flogi_cnt++;
+		qedf->flogi_pending++;
+
+		if (test_bit(QEDF_UNLOADING, &qedf->flags)) {
+			QEDF_ERR(&qedf->dbg_ctx, "Driver unloading\n");
+			qedf->flogi_pending = 0;
+		}
+
 		if (qedf->flogi_pending >= QEDF_FLOGI_RETRY_CNT) {
 			schedule_delayed_work(&qedf->stag_work, 2);
 			return NULL;
 		}
-		qedf->flogi_pending++;
+
 		return fc_elsct_send(lport, did, fp, op, qedf_flogi_resp,
 		    arg, timeout);
 	}
···
 	struct qedf_ctx *qedf;
 	struct qed_link_output if_link;
 
+	qedf = lport_priv(lport);
+
 	if (lport->vport) {
+		clear_bit(QEDF_STAG_IN_PROGRESS, &qedf->flags);
 		printk_ratelimited("Cannot issue host reset on NPIV port.\n");
 		return;
 	}
-
-	qedf = lport_priv(lport);
 
 	qedf->flogi_pending = 0;
 	/* For host reset, essentially do a soft link up/down */
···
 	if (!if_link.link_up) {
 		QEDF_INFO(&qedf->dbg_ctx, QEDF_LOG_DISC,
 			  "Physical link is not up.\n");
+		clear_bit(QEDF_STAG_IN_PROGRESS, &qedf->flags);
 		return;
 	}
 	/* Flush and wait to make sure link down is processed */
···
 		  "Queue link up work.\n");
 	queue_delayed_work(qedf->link_update_wq, &qedf->link_update,
 	    0);
+	clear_bit(QEDF_STAG_IN_PROGRESS, &qedf->flags);
 }
 
 /* Reset the host by gracefully logging out and then logging back in */
···
 {
 	struct qedf_ctx *qedf;
 	int rc;
+	int cnt = 0;
 
 	if (!pdev) {
 		QEDF_ERR(NULL, "pdev is NULL.\n");
···
 	if (test_bit(QEDF_UNLOADING, &qedf->flags)) {
 		QEDF_ERR(&qedf->dbg_ctx, "Already removing PCI function.\n");
 		return;
+	}
+
+stag_in_prog:
+	if (test_bit(QEDF_STAG_IN_PROGRESS, &qedf->flags)) {
+		QEDF_ERR(&qedf->dbg_ctx, "Stag in progress, cnt=%d.\n", cnt);
+		cnt++;
+
+		if (cnt < 5) {
+			msleep(500);
+			goto stag_in_prog;
+		}
 	}
 
 	if (mode != QEDF_MODE_RECOVERY)
···
 		QEDF_ERR(&qedf->dbg_ctx, "Driver unloading\n");
 		return;
 	}
+
+	set_bit(QEDF_STAG_IN_PROGRESS, &qedf->flags);
 
 	printk_ratelimited("[%s]:[%s:%d]:%d: Performing software context reset.",
 			dev_name(&qedf->pdev->dev), __func__, __LINE__,