--- zzzz-none-000/linux-3.10.107/drivers/block/paride/pd.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/block/paride/pd.c	2021-02-04 17:41:59.000000000 +0000
@@ -247,6 +247,8 @@
 	"IDNF", "MC", "UNC", "???", "TMO"
 };
 
+static void *par_drv;		/* reference of parport driver */
+
 static inline int status_reg(struct pd_unit *disk)
 {
 	return pi_read_regr(disk->pi, 1, 6);
@@ -442,7 +444,7 @@
 
 static enum action do_pd_io_start(void)
 {
-	if (pd_req->cmd_type == REQ_TYPE_SPECIAL) {
+	if (pd_req->cmd_type == REQ_TYPE_DRV_PRIV) {
 		phase = pd_special;
 		return pd_special();
 	}
@@ -454,7 +456,7 @@
 		if (pd_block + pd_count > get_capacity(pd_req->rq_disk))
 			return Fail;
 		pd_run = blk_rq_sectors(pd_req);
-		pd_buf = pd_req->buffer;
+		pd_buf = bio_data(pd_req->bio);
 		pd_retries = 0;
 		if (pd_cmd == READ)
 			return do_pd_read_start();
@@ -485,7 +487,7 @@
 	spin_lock_irqsave(&pd_lock, saved_flags);
 	__blk_end_request_cur(pd_req, 0);
 	pd_count = blk_rq_cur_sectors(pd_req);
-	pd_buf = pd_req->buffer;
+	pd_buf = bio_data(pd_req->bio);
 	spin_unlock_irqrestore(&pd_lock, saved_flags);
 	return 0;
 }
@@ -721,9 +723,11 @@
 	struct request *rq;
 	int err = 0;
 
-	rq = blk_get_request(disk->gd->queue, READ, __GFP_WAIT);
+	rq = blk_get_request(disk->gd->queue, READ, __GFP_RECLAIM);
+	if (IS_ERR(rq))
+		return PTR_ERR(rq);
 
-	rq->cmd_type = REQ_TYPE_SPECIAL;
+	rq->cmd_type = REQ_TYPE_DRV_PRIV;
 	rq->special = func;
 
 	err = blk_execute_rq(disk->gd->queue, disk->gd, rq, 0);
@@ -870,6 +874,12 @@
 			pd_drive_count++;
 	}
 
+	par_drv = pi_register_driver(name);
+	if (!par_drv) {
+		pr_err("failed to register %s driver\n", name);
+		return -1;
+	}
+
 	if (pd_drive_count == 0) { /* nothing spec'd - so autoprobe for 1 */
 		disk = pd;
 		if (pi_init(disk->pi, 1, -1, -1, -1, -1, -1, pd_scratch,
@@ -900,8 +910,10 @@
 			found = 1;
 		}
 	}
-	if (!found)
+	if (!found) {
 		printk("%s: no valid drive found\n", name);
+		pi_unregister_driver(par_drv);
+	}
 	return found;
 }