console: Add callback to flush scrollback buffer to consw struct

This new callback is in preparation for persistent scrollback buffer
support for VGA consoles.
With a single scrollback buffer for all consoles, we could flush the
buffer just by invocating consw->con_switch(). But when each VGA console
has its own scrollback buffer, we need a new callback to tell the
video console driver which buffer to flush.

Signed-off-by: Manuel Schölling <manuel.schoelling@gmx.de>
Reviewed-by: Andrey Utkin <andrey_utkin@fastmail.com>
Tested-by: Andrey Utkin <andrey_utkin@fastmail.com>
Tested-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 4c10a9df3b91..9d3ce505e7ab 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -625,6 +625,14 @@ static void save_screen(struct vc_data *vc)
                 vc->vc_sw->con_save_screen(vc);
 }
 
+static void flush_scrollback(struct vc_data *vc)
+{
+        WARN_CONSOLE_UNLOCKED();
+
+        if (vc->vc_sw->con_flush_scrollback)
+                vc->vc_sw->con_flush_scrollback(vc);
+}
+
 /*
  *      Redrawing of screen
  */
@@ -1171,6 +1179,7 @@ static void csi_J(struct vc_data *vc, int vpar)
                 case 3: /* erase scroll-back buffer (and whole display) */
                         scr_memsetw(vc->vc_screenbuf, vc->vc_video_erase_char,
                                     vc->vc_screenbuf_size);
+                        flush_scrollback(vc);
                         set_origin(vc);
                         if (con_is_visible(vc))
                                 update_screen(vc);