[PATCH] uml: Add throttling to console driver

This patch adds support for throttling and unthrottling input when the tty
driver can't handle it.

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

2 files changed, 6 insertions, 0 deletions

diff --git a/arch/um/include/chan_kern.h b/arch/um/include/chan_kern.h
index 84d1f64f9795..1bb5e9d94270 100644
--- a/arch/um/include/chan_kern.h
+++ b/arch/um/include/chan_kern.h
@@ -38,6 +38,8 @@ extern int console_write_chan(struct list_head *chans, const char *buf,
                               int len);
 extern int console_open_chan(struct line *line, struct console *co,
                              struct chan_opts *opts);
+extern void deactivate_chan(struct list_head *chans, int irq);
+extern void reactivate_chan(struct list_head *chans, int irq);
 extern void chan_enable_winch(struct list_head *chans, struct tty_struct *tty);
 extern void enable_chan(struct line *line);
 extern void close_chan(struct list_head *chans, int delay_free_irq);
diff --git a/arch/um/include/line.h b/arch/um/include/line.h
index e6cc3abfd4db..6f4d680dc1d4 100644
--- a/arch/um/include/line.h
+++ b/arch/um/include/line.h
@@ -38,6 +38,7 @@ struct line {
         struct list_head chan_list;
         int valid;
         int count;
+        int throttled;
         /*This lock is actually, mostly, local to*/
         spinlock_t lock;
 
@@ -60,6 +61,7 @@ struct line {
         { init_str :    str, \
           init_pri :    INIT_STATIC, \
           valid :       1, \
+          throttled :   0, \
           lock :        SPIN_LOCK_UNLOCKED, \
           buffer :      NULL, \
           head :        NULL, \
@@ -88,6 +90,8 @@ extern void line_flush_chars(struct tty_struct *tty);
 extern int line_write_room(struct tty_struct *tty);
 extern int line_ioctl(struct tty_struct *tty, struct file * file,
                       unsigned int cmd, unsigned long arg);
+extern void line_throttle(struct tty_struct *tty);
+extern void line_unthrottle(struct tty_struct *tty);
 
 extern char *add_xterm_umid(char *base);
 extern int line_setup_irq(int fd, int input, int output, struct line *line,