[PATCH] uml: redo console locking

Fix some console locking problems (including scheduling in atomic) and various
reorderings and cleanup in that code.  Not yet ready for 2.6.12 probably.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 6 insertions, 13 deletions

diff --git a/arch/um/drivers/stdio_console.c b/arch/um/drivers/stdio_console.c
index e604d7c87695..361d0be342b3 100644
--- a/arch/um/drivers/stdio_console.c
+++ b/arch/um/drivers/stdio_console.c
@@ -116,8 +116,11 @@ static struct tty_operations console_ops = {
         .open                   = con_open,
         .close                  = line_close,
         .write                  = line_write,
+        .put_char               = line_put_char,
         .write_room             = line_write_room,
         .chars_in_buffer        = line_chars_in_buffer,
+        .flush_buffer           = line_flush_buffer,
+        .flush_chars            = line_flush_chars,
         .set_termios            = line_set_termios,
         .ioctl                  = line_ioctl,
 };
@@ -126,10 +129,11 @@ static void uml_console_write(struct console *console, const char *string,
                           unsigned len)
 {
         struct line *line = &vts[console->index];
+        unsigned long flags;
 
-        down(&line->sem);
+        spin_lock_irqsave(&line->lock, flags);
         console_write_chan(&line->chan_list, string, len);
-        up(&line->sem);
+        spin_unlock_irqrestore(&line->lock, flags);
 }
 
 static struct tty_driver *uml_console_device(struct console *c, int *index)
@@ -192,14 +196,3 @@ static int console_chan_setup(char *str)
 }
 __setup("con", console_chan_setup);
 __channel_help(console_chan_setup, "con");
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */