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Commit e4dcee80 authored by Jeff Dike's avatar Jeff Dike Committed by Linus Torvalds
Browse files

[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: default avatarJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 9159c9df

arch/um/drivers/chan_kern.c

+26 −0
Original line number Diff line number Diff line
@@ -312,6 +312,32 @@ void close_chan(struct list_head *chans, int delay_free_irq) 
	}

}



void deactivate_chan(struct list_head *chans, int irq)

{

	struct list_head *ele;



	struct chan *chan;

	list_for_each(ele, chans) {

		chan = list_entry(ele, struct chan, list);



		if(chan->enabled && chan->input)

			deactivate_fd(chan->fd, irq);

	}

}



void reactivate_chan(struct list_head *chans, int irq)

{

	struct list_head *ele;

	struct chan *chan;



	list_for_each(ele, chans) {

		chan = list_entry(ele, struct chan, list);



		if(chan->enabled && chan->input)

			reactivate_fd(chan->fd, irq);

	}

}



int write_chan(struct list_head *chans, const char *buf, int len,

	       int write_irq)

{

arch/um/drivers/line.c

+27 −2
Original line number Diff line number Diff line
@@ -36,6 +36,7 @@ static void line_timer_cb(void *arg) 
{

	struct line *line = arg;



	if(!line->throttled)

		chan_interrupt(&line->chan_list, &line->task, line->tty,

			       line->driver->read_irq);

}
@@ -340,6 +341,30 @@ int line_ioctl(struct tty_struct *tty, struct file * file, 
	return ret;

}



void line_throttle(struct tty_struct *tty)

{

	struct line *line = tty->driver_data;



	deactivate_chan(&line->chan_list, line->driver->read_irq);

	line->throttled = 1;

}



void line_unthrottle(struct tty_struct *tty)

{

	struct line *line = tty->driver_data;



	line->throttled = 0;

	chan_interrupt(&line->chan_list, &line->task, tty,

		       line->driver->read_irq);



	/* Maybe there is enough stuff pending that calling the interrupt

	 * throttles us again.  In this case, line->throttled will be 1

	 * again and we shouldn't turn the interrupt back on.

	 */

	if(!line->throttled)

		reactivate_chan(&line->chan_list, line->driver->read_irq);

}



static irqreturn_t line_write_interrupt(int irq, void *data,

					struct pt_regs *unused)

{

arch/um/drivers/ssl.c

+2 −12
Original line number Diff line number Diff line
@@ -109,16 +109,6 @@ static void ssl_flush_buffer(struct tty_struct *tty) 
	return;

}



static void ssl_throttle(struct tty_struct * tty)

{

	printk(KERN_ERR "Someone should implement ssl_throttle\n");

}



static void ssl_unthrottle(struct tty_struct * tty)

{

	printk(KERN_ERR "Someone should implement ssl_unthrottle\n");

}



static void ssl_stop(struct tty_struct *tty)

{

	printk(KERN_ERR "Someone should implement ssl_stop\n");
@@ -145,9 +135,9 @@ static struct tty_operations ssl_ops = { 
	.flush_chars 		= line_flush_chars,

	.set_termios 		= line_set_termios,

	.ioctl 	 		= line_ioctl,

	.throttle 		= line_throttle,

	.unthrottle 		= line_unthrottle,

#if 0

	.throttle 		= ssl_throttle,

	.unthrottle 		= ssl_unthrottle,

	.stop 	 		= ssl_stop,

	.start 	 		= ssl_start,

	.hangup 	 	= ssl_hangup,

arch/um/drivers/stdio_console.c

+2 −0
Original line number Diff line number Diff line
@@ -122,6 +122,8 @@ static struct tty_operations console_ops = { 
	.flush_chars 		= line_flush_chars,

	.set_termios 		= line_set_termios,

	.ioctl 	 		= line_ioctl,

	.throttle 		= line_throttle,

	.unthrottle 		= line_unthrottle,

};



static void uml_console_write(struct console *console, const char *string,

arch/um/include/chan_kern.h

+2 −0
Original line number Diff line number Diff line
@@ -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);