gdm/SOURCES/0025-session-worker-clear-VT-before-jumping-to-it.patch
2021-09-09 17:04:10 +00:00

91 lines
3.3 KiB
Diff

From cabcd21c17ca98e517a3eea7c9d5ce269445e3e0 Mon Sep 17 00:00:00 2001
From: Ray Strode <rstrode@redhat.com>
Date: Fri, 31 Aug 2018 15:46:55 -0400
Subject: [PATCH 25/51] session-worker: clear VT before jumping to it
If we're going to jump to a new VT we should make sure it's free
of residual console text. That way if there's flicker the user
will be less likely to notice it.
This commit sends a clear screen escape sequence to the tty
before jumping to it.
---
daemon/gdm-session-worker.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/daemon/gdm-session-worker.c b/daemon/gdm-session-worker.c
index 391969d96..7ed2789da 100644
--- a/daemon/gdm-session-worker.c
+++ b/daemon/gdm-session-worker.c
@@ -943,60 +943,67 @@ fix_terminal_vt_mode (GdmSessionWorker *worker,
}
/* VT is in the anti-social state of VT_AUTO + KD_GRAPHICS,
* fix it.
*/
succeeded = handle_terminal_vt_switches (worker, tty_fd);
mode_fixed = TRUE;
out:
if (!succeeded) {
g_error ("GdmSessionWorker: couldn't set up terminal, aborting...");
return;
}
g_debug ("GdmSessionWorker: VT mode did %sneed to be fixed",
mode_fixed? "" : "not ");
}
static void
jump_to_vt (GdmSessionWorker *worker,
int vt_number)
{
int fd;
int active_vt_tty_fd;
int active_vt = -1;
struct vt_stat vt_state = { 0 };
g_debug ("GdmSessionWorker: jumping to VT %d", vt_number);
active_vt_tty_fd = open ("/dev/tty0", O_RDWR | O_NOCTTY);
if (worker->priv->session_tty_fd != -1) {
+ static const char *clear_screen_escape_sequence = "\33[H\33[2J";
+
+ /* let's make sure the new VT is clear */
+ write (worker->priv->session_tty_fd,
+ clear_screen_escape_sequence,
+ sizeof (clear_screen_escape_sequence));
+
fd = worker->priv->session_tty_fd;
g_debug ("GdmSessionWorker: first setting graphics mode to prevent flicker");
if (ioctl (fd, KDSETMODE, KD_GRAPHICS) < 0) {
g_debug ("GdmSessionWorker: couldn't set graphics mode: %m");
}
/* It's possible that the current VT was left in a broken
* combination of states (KD_GRAPHICS with VT_AUTO), that
* can't be switched away from. This call makes sure things
* are set in a way that VT_ACTIVATE should work and
* VT_WAITACTIVE shouldn't hang.
*/
fix_terminal_vt_mode (worker, active_vt_tty_fd);
} else {
fd = active_vt_tty_fd;
}
handle_terminal_vt_switches (worker, fd);
if (ioctl (fd, VT_GETSTATE, &vt_state) < 0) {
g_debug ("GdmSessionWorker: couldn't get current VT: %m");
} else {
active_vt = vt_state.v_active;
}
if (active_vt != vt_number) {
if (ioctl (fd, VT_ACTIVATE, vt_number) < 0) {
g_debug ("GdmSessionWorker: couldn't initiate jump to VT %d: %m",
vt_number);
--
2.27.0