um: switch line.c tty drivers to dynamic device creation

Current code doesn't update the symlinks in /sys/dev/char when we add/remove
tty lines.  Fixing that allows to stop messing with ->valid before the driver
registration, which is a Good Thing(tm) - we shouldn't have it set before we
really have the things set up and ready for line_open().

We need tty_driver available to call tty_{un,}register_device(), so we just
stash a reference to it into struct line_driver.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

1 files changed, 6 insertions, 13 deletions

diff --git a/arch/um/drivers/stdio_console.c b/arch/um/drivers/stdio_console.c
index f8d4325b28b7..32bd040138f0 100644
--- a/arch/um/drivers/stdio_console.c
+++ b/arch/um/drivers/stdio_console.c
@@ -27,12 +27,6 @@
 
 #define MAX_TTYS (16)
 
-/* Referenced only by tty_driver below - presumably it's locked correctly
- * by the tty driver.
- */
-
-static struct tty_driver *console_driver;
-
 static void stdio_announce(char *dev_name, int dev)
 {
         printk(KERN_INFO "Virtual console %d assigned device '%s'\n", dev,
@@ -137,7 +131,7 @@ static void uml_console_write(struct console *console, const char *string,
 static struct tty_driver *uml_console_device(struct console *c, int *index)
 {
         *index = c->index;
-        return console_driver;
+        return driver.driver;
 }
 
 static int uml_console_setup(struct console *co, char *options)
@@ -160,6 +154,7 @@ static struct console stdiocons = {
 static int stdio_init(void)
 {
         char *new_title;
+        int err;
         int i;
 
         for (i = 0; i < MAX_TTYS; i++) {
@@ -168,18 +163,16 @@ static int stdio_init(void)
                         s = def_conf;
                 if (!s)
                         s = i ? CONFIG_CON_CHAN : CONFIG_CON_ZERO_CHAN;
-                if (s && strcmp(s, "none") != 0) {
+                if (s && strcmp(s, "none") != 0)
                         vts[i].init_str = s;
-                        vts[i].valid = 1;
-                }
                 spin_lock_init(&vts[i].lock);
                 mutex_init(&vts[i].count_lock);
                 vts[i].driver = &driver;
         }
-        console_driver = register_lines(&driver, &console_ops, vts,
+        err = register_lines(&driver, &console_ops, vts,
                                         ARRAY_SIZE(vts));
-        if (console_driver == NULL)
-                return -1;
+        if (err)
+                return err;
         printk(KERN_INFO "Initialized stdio console driver\n");
 
         new_title = add_xterm_umid(opts.xterm_title);