--- zzzz-none-000/linux-3.10.107/drivers/s390/char/con3270.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/s390/char/con3270.c	2021-02-04 17:41:59.000000000 +0000
@@ -7,6 +7,7 @@
  *     Copyright IBM Corp. 2003, 2009
  */
 
+#include <linux/module.h>
 #include <linux/console.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
@@ -30,6 +31,9 @@
 
 static struct raw3270_fn con3270_fn;
 
+static bool auto_update = 1;
+module_param(auto_update, bool, 0);
+
 /*
  * Main 3270 console view data structure.
  */
@@ -120,7 +124,12 @@
 static void
 con3270_update_string(struct con3270 *cp, struct string *s, int nr)
 {
-	if (s->len >= cp->view.cols - 5)
+	if (s->len < 4) {
+		/* This indicates a bug, but printing a warning would
+		 * cause a deadlock. */
+		return;
+	}
+	if (s->string[s->len - 4] != TO_RA)
 		return;
 	raw3270_buffer_address(cp->view.dev, s->string + s->len - 3,
 			       cp->view.cols * (nr + 1));
@@ -204,6 +213,8 @@
 	struct string *s, *n;
 	int rc;
 
+	if (!auto_update && !raw3270_view_active(&cp->view))
+		return;
 	if (cp->view.dev)
 		raw3270_activate_view(&cp->view);
 
@@ -407,6 +418,10 @@
 		else
 			/* Normal end. Copy residual count. */
 			rq->rescnt = irb->scsw.cmd.count;
+	} else if (irb->scsw.cmd.dstat & DEV_STAT_DEV_END) {
+		/* Interrupt without an outstanding request -> update all */
+		cp->update_flags = CON_UPDATE_ALL;
+		con3270_set_timer(cp, 1);
 	}
 	return RAW3270_IO_DONE;
 }
@@ -451,11 +466,11 @@
 		cp->cline->len + 4 : cp->view.cols;
 	s = con3270_alloc_string(cp, size);
 	memcpy(s->string, cp->cline->string, cp->cline->len);
-	if (s->len < cp->view.cols - 5) {
+	if (cp->cline->len < cp->view.cols - 5) {
 		s->string[s->len - 4] = TO_RA;
 		s->string[s->len - 1] = 0;
 	} else {
-		while (--size > cp->cline->len)
+		while (--size >= cp->cline->len)
 			s->string[size] = cp->view.ascebc[' '];
 	}
 	/* Replace cline with allocated line s and reset cline. */
@@ -529,6 +544,7 @@
 	if (!cp->view.dev)
 		return;
 	raw3270_pm_unfreeze(&cp->view);
+	raw3270_activate_view(&cp->view);
 	spin_lock_irqsave(&cp->view.lock, flags);
 	con3270_wait_write(cp);
 	cp->nr_up = 0;