From: Julien Muchembled <jm@jmuchemb.eu>
Date: Mon, 23 Dec 2013 06:30:06 +0100
Subject: New option to change VT

When invoked with -vN (or --chvt=N) option, userui makes /dev/ttyN the
foreground terminal before doing anything else, and restore previous VT at exit.
If /dev/ttyN is already the foreground terminal, the new option does nothing.
There's also no change in behaviour if this new option is not passed.

TOI UI needs its own VT and without such option, it would be required
to work around this in every power management hibernation.
---
 fbsplash/cmd.c                  | 11 ++++----
 fbsplash/common.c               |  1 -
 fbsplash/splash.h               |  1 -
 fbsplash/userui_fbsplash_core.c | 22 ----------------
 userui.h                        |  1 +
 userui_core.c                   | 56 +++++++++++++++++++++++++++++++++++++----
 userui_text.c                   |  2 --
 7 files changed, 58 insertions(+), 36 deletions(-)

diff --git a/fbsplash/cmd.c b/fbsplash/cmd.c
index 2672d69..0a418df 100644
--- a/fbsplash/cmd.c
+++ b/fbsplash/cmd.c
@@ -25,6 +25,7 @@
 #include <errno.h>
 #include <linux/fb.h>
 #include "splash.h"
+#include "../userui.h"
 
 #ifdef CONFIG_FBSPLASH
 #include <linux/console_splash.h>
@@ -32,7 +33,7 @@
 void cmd_setstate(unsigned int state, unsigned char origin)
 {
 	struct fb_splash_iowrapper wrapper = {
-		.vc = arg_vc,
+		.vc = suspend_vt,
 		.origin = origin,
 		.data = &state,
 	};
@@ -46,7 +47,7 @@ void cmd_setstate(unsigned int state, unsigned char origin)
 void cmd_setpic(struct fb_image *img, unsigned char origin)
 {
 	struct fb_splash_iowrapper wrapper = {
-		.vc = arg_vc,
+		.vc = suspend_vt,
 		.origin = origin,
 		.data = img,
 	};
@@ -60,7 +61,7 @@ void cmd_setcfg(unsigned char origin)
 {
 	struct vc_splash vc_cfg;
 	struct fb_splash_iowrapper wrapper = {
-		.vc = arg_vc,
+		.vc = suspend_vt,
 		.origin = origin,
 		.data = &vc_cfg,
 	};
@@ -82,7 +83,7 @@ void cmd_getcfg()
 {
 	struct vc_splash vc_cfg;
 	struct fb_splash_iowrapper wrapper = {
-		.vc = arg_vc,
+		.vc = suspend_vt,
 		.origin = FB_SPLASH_IO_ORIG_USER,
 		.data = &vc_cfg,
 	};
@@ -97,7 +98,7 @@ void cmd_getcfg()
 		strcpy(vc_cfg.theme, "<none>");
 	} 
 		
-	printf("Splash config on console %d:\n", arg_vc);
+	printf("Splash config on console %d:\n", suspend_vt);
 	printf("tx:       %d\n", vc_cfg.tx);
 	printf("ty:	  %d\n", vc_cfg.ty);
 	printf("twidth:	  %d\n", vc_cfg.twidth);
diff --git a/fbsplash/common.c b/fbsplash/common.c
index fb34c7c..370007d 100644
--- a/fbsplash/common.c
+++ b/fbsplash/common.c
@@ -37,7 +37,6 @@ char *config_file = NULL;
 
 enum TASK arg_task = none; 
 int arg_fb = 0;
-int arg_vc = 0;
 char arg_mode = 'v';
 char *arg_theme = NULL;
 u16 arg_progress = 0;
diff --git a/fbsplash/splash.h b/fbsplash/splash.h
index 4b37ff1..bd0d100 100644
--- a/fbsplash/splash.h
+++ b/fbsplash/splash.h
@@ -265,7 +265,6 @@ extern struct fb_fix_screeninfo   fb_fix;
 extern enum ENDIANESS endianess;
 extern enum TASK arg_task;
 extern int arg_fb;
-extern int arg_vc;
 extern char *arg_theme;
 extern char arg_mode;
 extern u16 arg_progress;
diff --git a/fbsplash/userui_fbsplash_core.c b/fbsplash/userui_fbsplash_core.c
index 2a4099b..09f1504 100644
--- a/fbsplash/userui_fbsplash_core.c
+++ b/fbsplash/userui_fbsplash_core.c
@@ -67,27 +67,6 @@ static void silent_off() {
 	show_cursor();
 }
 
-static int get_active_vt() {
-	int vt, fd;
-	struct vt_stat vt_stat;
-
-	vt = 62; /* default */
-
-	if ((fd = open("/dev/tty0", O_RDONLY)) == -1)
-		goto out;
-
-	if (ioctl(fd, VT_GETSTATE, &vt_stat) == -1)
-		goto out;
-
-	vt = vt_stat.v_active - 1;
-
-out:
-	if (fd >= 0)
-		close(fd);
-
-	return vt;
-}
-
 static int fbsplash_load() {
 	fb_fd = -1;
 	last_pos = 0;
@@ -103,7 +82,6 @@ static int fbsplash_load() {
 		return 1;
 	}
 
-	arg_vc = get_active_vt();
 	arg_mode = 's';
 
 	/* Read theme config file */
diff --git a/userui.h b/userui.h
index ca59826..920f704 100644
--- a/userui.h
+++ b/userui.h
@@ -53,6 +53,7 @@ void printk(char *msg, ...);
 
 extern char software_suspend_version[32];
 extern int can_use_escape;
+extern int suspend_vt;
 extern volatile __uint32_t console_loglevel;
 extern volatile __uint32_t suspend_action;
 extern volatile __uint32_t suspend_debug;
diff --git a/userui_core.c b/userui_core.c
index 74d7aa6..5e3f713 100644
--- a/userui_core.c
+++ b/userui_core.c
@@ -96,6 +96,8 @@ static void might_switch_ops(void)
 }
 
 static int netlink_socket_num = 0;
+static int saved_vt = 0;
+int suspend_vt = 0;
 
 static char* descriptions[] = {
 	"General",
@@ -373,7 +375,7 @@ int common_keypress_handler(int key)
 }
 
 static void handle_params(int argc, char **argv) {
-	static char global_optstring[] = "htc:fu";
+	static char global_optstring[] = "htc:fuv:";
 	static struct option global_longopts[] = {
 		{"help", 0, 0, 'h'},
 		{"test", 0, 0, 't'},
@@ -382,6 +384,7 @@ static void handle_params(int argc, char **argv) {
 #ifdef USE_USPLASH
 		{"usplash", 0, 0, 'u'},
 #endif
+		{"chvt", 1, 0, 'v'},
 		{NULL, 0, 0, 0},
 	};
 
@@ -437,6 +440,9 @@ static void handle_params(int argc, char **argv) {
 			case 't':
 				test_run++;
 				break;
+			case 'v':
+				suspend_vt = atoi(optarg);
+				break;
 			case 'h':
 				fprintf(stderr,
 "Usage: %s [options]\n"
@@ -445,6 +451,9 @@ static void handle_params(int argc, char **argv) {
 "     Specifying -t once will give an demo of this module.\n"
 "     Specifying -t twice will make the demo run as fast as it can.\n"
 "     (useful for performance testing).\n"
+"  -v, --chvt=N\n"
+"     Makes /dev/ttyN the foreground terminal before doing anything else\n"
+"     and restore previous VT at the end.\n"
 #ifdef USE_USPLASH
 "  -u\n"
 "     Use usersplash interface by default.\n"
@@ -603,6 +612,27 @@ static void enforce_lifesavers() {
 	setrlimit(RLIMIT_CORE, &r);
 }
 
+static int chvt(int vt) {
+	return ioctl(console_fd, VT_ACTIVATE, vt)
+	    || ioctl(console_fd, VT_WAITACTIVE, vt)
+	    || close(console_fd)
+	    || (console_fd = open("/dev/console", O_RDWR)) == -1;
+}
+
+static void restore_vt() {
+	struct rlimit r;
+	r.rlim_cur = r.rlim_max = console_fd + 1;
+	setrlimit(RLIMIT_NOFILE, &r);
+	close(STDOUT_FILENO);
+	close(STDERR_FILENO);
+	/* It does not matter whether other files are still opened or not.
+	 * RLIMIT_NOFILE only prevents files from being opened with a fd greater
+	 * or equal than the limit. chvt should reopen console with fd=0
+	 */
+	chvt(saved_vt);
+	ioctl(console_fd, VT_DISALLOCATE, suspend_vt);
+}
+
 static void restore_console() {
 	int result;
 	ioctl(console_fd, KDSKBMODE, K_XLATE);
@@ -726,14 +756,30 @@ static void setup_signal_handlers() {
 }
 
 static void open_console() {
+	struct vt_stat vtstat;
+
 	if ((console_fd = open("/dev/console", O_RDWR)) == -1)
 		bail_err("open(\"/dev/console\", O_RDWR)");
 
-	if (dup2(console_fd, STDIN_FILENO) == -1)
-		bail_err("dup2(fd, STDIN_FILENO)");
-	if (!test_run && dup2(console_fd, STDOUT_FILENO) == -1)
+	if (ioctl(console_fd, VT_GETSTATE, &vtstat))
+		bail_err("VT_GETSTATE");
+	if (!suspend_vt)
+		suspend_vt = vtstat.v_active;
+	else if (suspend_vt != vtstat.v_active) {
+		if (chvt(suspend_vt))
+			bail_err("failed to change VT");
+		saved_vt = vtstat.v_active;
+		atexit(restore_vt);
+	}
+
+	if (console_fd != STDIN_FILENO) {
+		if (dup2(console_fd, STDIN_FILENO) == -1 || close(console_fd))
+			bail_err("dup2(fd, STDIN_FILENO)");
+		console_fd = STDIN_FILENO;
+	}
+	if (dup2(console_fd, STDOUT_FILENO) == -1)
 		bail_err("dup2(fd, STDOUT_FILENO)");
-	if (!test_run && dup2(console_fd, STDERR_FILENO) == -1)
+	if (dup2(console_fd, STDERR_FILENO) == -1)
 		bail_err("dup2(fd, STDERR_FILENO)");
 }
 
diff --git a/userui_text.c b/userui_text.c
index 0b9ff2a..5502f4b 100644
--- a/userui_text.c
+++ b/userui_text.c
@@ -362,8 +362,6 @@ static void text_cleanup()
 		close(vcsa_fd);
 
 	ioctl(STDOUT_FILENO, TCSETSF, (long)&termios);
-
-	/* chvt back? */
 }
 
 static void text_redraw()