vt: provide notifications on selection changes

commit 19e3ae6b4f07a87822c1c9e7ed99d31860e701af upstream.

The vcs device's poll/fasync support relies on the vt notifier to signal
changes to the screen content.  Notifier invocations were missing for
changes that comes through the selection interface though.  Fix that.

Tested with BRLTTY 5.2.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Cc: Dave Mielke <dave@mielke.cc>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 0d1b375..db9d69f 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -498,6 +498,7 @@
 #endif
 	if (DO_UPDATE(vc))
 		do_update_region(vc, (unsigned long) p, count);
+	notify_update(vc);
 }
 
 /* used by selection: complement pointer position */
@@ -514,6 +515,7 @@
 		scr_writew(old, screenpos(vc, old_offset, 1));
 		if (DO_UPDATE(vc))
 			vc->vc_sw->con_putc(vc, old, oldy, oldx);
+		notify_update(vc);
 	}
 
 	old_offset = offset;
@@ -531,8 +533,8 @@
 			oldy = (offset >> 1) / vc->vc_cols;
 			vc->vc_sw->con_putc(vc, new, oldy, oldx);
 		}
+		notify_update(vc);
 	}
-
 }
 
 static void insert_char(struct vc_data *vc, unsigned int nr)