15 files changed, 292 insertions, 366 deletions

diff --git a/arch/um/drivers/chan.h b/arch/um/drivers/chan.h
index 8df0fd9024dc..02b5a76e98d9 100644
--- a/arch/um/drivers/chan.h
+++ b/arch/um/drivers/chan.h
@@ -27,24 +27,24 @@ struct chan {
 	void *data;
 };
 
-extern void chan_interrupt(struct list_head *chans, struct delayed_work *task,
+extern void chan_interrupt(struct line *line,
 			   struct tty_struct *tty, int irq);
 extern int parse_chan_pair(char *str, struct line *line, int device,
 			   const struct chan_opts *opts, char **error_out);
-extern int write_chan(struct list_head *chans, const char *buf, int len,
+extern int write_chan(struct chan *chan, const char *buf, int len,
 			     int write_irq);
-extern int console_write_chan(struct list_head *chans, const char *buf, 
+extern int console_write_chan(struct chan *chan, const char *buf, 
 			      int len);
 extern int console_open_chan(struct line *line, struct console *co);
-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 deactivate_chan(struct chan *chan, int irq);
+extern void reactivate_chan(struct chan *chan, int irq);
+extern void chan_enable_winch(struct chan *chan, struct tty_struct *tty);
 extern int enable_chan(struct line *line);
-extern void close_chan(struct list_head *chans, int delay_free_irq);
-extern int chan_window_size(struct list_head *chans, 
+extern void close_chan(struct line *line);
+extern int chan_window_size(struct line *line, 
 			     unsigned short *rows_out, 
 			     unsigned short *cols_out);
-extern int chan_config_string(struct list_head *chans, char *str, int size,
+extern int chan_config_string(struct line *line, char *str, int size,
 			      char **error_out);
 
 #endif
diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
index 420e2c800799..ca4c7ebfd0aa 100644
--- a/arch/um/drivers/chan_kern.c
+++ b/arch/um/drivers/chan_kern.c
@@ -140,18 +140,18 @@ static int open_chan(struct list_head *chans)
 	return err;
 }
 
-void chan_enable_winch(struct list_head *chans, struct tty_struct *tty)
+void chan_enable_winch(struct chan *chan, struct tty_struct *tty)
 {
-	struct list_head *ele;
-	struct chan *chan;
+	if (chan && chan->primary && chan->ops->winch)
+		register_winch(chan->fd, tty);
+}
 
-	list_for_each(ele, chans) {
-		chan = list_entry(ele, struct chan, list);
-		if (chan->primary && chan->output && chan->ops->winch) {
-			register_winch(chan->fd, tty);
-			return;
-		}
-	}
+static void line_timer_cb(struct work_struct *work)
+{
+	struct line *line = container_of(work, struct line, task.work);
+
+	if (!line->throttled)
+		chan_interrupt(line, line->tty, line->driver->read_irq);
 }
 
 int enable_chan(struct line *line)
@@ -160,6 +160,8 @@ int enable_chan(struct line *line)
 	struct chan *chan;
 	int err;
 
+	INIT_DELAYED_WORK(&line->task, line_timer_cb);
+
 	list_for_each(ele, &line->chan_list) {
 		chan = list_entry(ele, struct chan, list);
 		err = open_one_chan(chan);
@@ -183,7 +185,7 @@ int enable_chan(struct line *line)
 	return 0;
 
  out_close:
-	close_chan(&line->chan_list, 0);
+	close_chan(line);
 	return err;
 }
 
@@ -244,7 +246,7 @@ static void close_one_chan(struct chan *chan, int delay_free_irq)
 	chan->fd = -1;
 }
 
-void close_chan(struct list_head *chans, int delay_free_irq)
+void close_chan(struct line *line)
 {
 	struct chan *chan;
 
@@ -253,77 +255,50 @@ void close_chan(struct list_head *chans, int delay_free_irq)
 	 * state.  Then, the first one opened will have the original state,
 	 * so it must be the last closed.
 	 */
-	list_for_each_entry_reverse(chan, chans, list) {
-		close_one_chan(chan, delay_free_irq);
+	list_for_each_entry_reverse(chan, &line->chan_list, list) {
+		close_one_chan(chan, 0);
 	}
 }
 
-void deactivate_chan(struct list_head *chans, int irq)
+void deactivate_chan(struct chan *chan, 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);
-	}
+	if (chan && chan->enabled)
+		deactivate_fd(chan->fd, irq);
 }
 
-void reactivate_chan(struct list_head *chans, int irq)
+void reactivate_chan(struct chan *chan, 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);
-	}
+	if (chan && chan->enabled)
+		reactivate_fd(chan->fd, irq);
 }
 
-int write_chan(struct list_head *chans, const char *buf, int len,
+int write_chan(struct chan *chan, const char *buf, int len,
 	       int write_irq)
 {
-	struct list_head *ele;
-	struct chan *chan = NULL;
 	int n, ret = 0;
 
-	if (len == 0)
+	if (len == 0 || !chan || !chan->ops->write)
 		return 0;
 
-	list_for_each(ele, chans) {
-		chan = list_entry(ele, struct chan, list);
-		if (!chan->output || (chan->ops->write == NULL))
-			continue;
-
-		n = chan->ops->write(chan->fd, buf, len, chan->data);
-		if (chan->primary) {
-			ret = n;
-			if ((ret == -EAGAIN) || ((ret >= 0) && (ret < len)))
-				reactivate_fd(chan->fd, write_irq);
-		}
+	n = chan->ops->write(chan->fd, buf, len, chan->data);
+	if (chan->primary) {
+		ret = n;
+		if ((ret == -EAGAIN) || ((ret >= 0) && (ret < len)))
+			reactivate_fd(chan->fd, write_irq);
 	}
 	return ret;
 }
 
-int console_write_chan(struct list_head *chans, const char *buf, int len)
+int console_write_chan(struct chan *chan, const char *buf, int len)
 {
-	struct list_head *ele;
-	struct chan *chan;
 	int n, ret = 0;
 
-	list_for_each(ele, chans) {
-		chan = list_entry(ele, struct chan, list);
-		if (!chan->output || (chan->ops->console_write == NULL))
-			continue;
+	if (!chan || !chan->ops->console_write)
+		return 0;
 
-		n = chan->ops->console_write(chan->fd, buf, len);
-		if (chan->primary)
-			ret = n;
-	}
+	n = chan->ops->console_write(chan->fd, buf, len);
+	if (chan->primary)
+		ret = n;
 	return ret;
 }
 
@@ -340,20 +315,24 @@ int console_open_chan(struct line *line, struct console *co)
 	return 0;
 }
 
-int chan_window_size(struct list_head *chans, unsigned short *rows_out,
+int chan_window_size(struct line *line, unsigned short *rows_out,
 		      unsigned short *cols_out)
 {
-	struct list_head *ele;
 	struct chan *chan;
 
-	list_for_each(ele, chans) {
-		chan = list_entry(ele, struct chan, list);
-		if (chan->primary) {
-			if (chan->ops->window_size == NULL)
-				return 0;
-			return chan->ops->window_size(chan->fd, chan->data,
-						      rows_out, cols_out);
-		}
+	chan = line->chan_in;
+	if (chan && chan->primary) {
+		if (chan->ops->window_size == NULL)
+			return 0;
+		return chan->ops->window_size(chan->fd, chan->data,
+					      rows_out, cols_out);
+	}
+	chan = line->chan_out;
+	if (chan && chan->primary) {
+		if (chan->ops->window_size == NULL)
+			return 0;
+		return chan->ops->window_size(chan->fd, chan->data,
+					      rows_out, cols_out);
 	}
 	return 0;
 }
@@ -429,21 +408,15 @@ static int chan_pair_config_string(struct chan *in, struct chan *out,
 	return n;
 }
 
-int chan_config_string(struct list_head *chans, char *str, int size,
+int chan_config_string(struct line *line, char *str, int size,
 		       char **error_out)
 {
-	struct list_head *ele;
-	struct chan *chan, *in = NULL, *out = NULL;
+	struct chan *in = line->chan_in, *out = line->chan_out;
 
-	list_for_each(ele, chans) {
-		chan = list_entry(ele, struct chan, list);
-		if (!chan->primary)
-			continue;
-		if (chan->input)
-			in = chan;
-		if (chan->output)
-			out = chan;
-	}
+	if (in && !in->primary)
+		in = NULL;
+	if (out && !out->primary)
+		out = NULL;
 
 	return chan_pair_config_string(in, out, str, size, error_out);
 }
@@ -547,10 +520,14 @@ int parse_chan_pair(char *str, struct line *line, int device,
 	char *in, *out;
 
 	if (!list_empty(chans)) {
+		line->chan_in = line->chan_out = NULL;
 		free_chan(chans);
 		INIT_LIST_HEAD(chans);
 	}
 
+	if (!str)
+		return 0;
+
 	out = strchr(str, ',');
 	if (out != NULL) {
 		in = str;
@@ -562,6 +539,7 @@ int parse_chan_pair(char *str, struct line *line, int device,
 
 		new->input = 1;
 		list_add(&new->list, chans);
+		line->chan_in = new;
 
 		new = parse_chan(line, out, device, opts, error_out);
 		if (new == NULL)
@@ -569,6 +547,7 @@ int parse_chan_pair(char *str, struct line *line, int device,
 
 		list_add(&new->list, chans);
 		new->output = 1;
+		line->chan_out = new;
 	}
 	else {
 		new = parse_chan(line, str, device, opts, error_out);
@@ -578,43 +557,42 @@ int parse_chan_pair(char *str, struct line *line, int device,
 		list_add(&new->list, chans);
 		new->input = 1;
 		new->output = 1;
+		line->chan_in = line->chan_out = new;
 	}
 	return 0;
 }
 
-void chan_interrupt(struct list_head *chans, struct delayed_work *task,
-		    struct tty_struct *tty, int irq)
+void chan_interrupt(struct line *line, struct tty_struct *tty, int irq)
 {
-	struct list_head *ele, *next;
-	struct chan *chan;
+	struct chan *chan = line->chan_in;
 	int err;
 	char c;
 
-	list_for_each_safe(ele, next, chans) {
-		chan = list_entry(ele, struct chan, list);
-		if (!chan->input || (chan->ops->read == NULL))
-			continue;
-		do {
-			if (tty && !tty_buffer_request_room(tty, 1)) {
-				schedule_delayed_work(task, 1);
-				goto out;
-			}
-			err = chan->ops->read(chan->fd, &c, chan->data);
-			if (err > 0)
-				tty_receive_char(tty, c);
-		} while (err > 0);
-
-		if (err == 0)
-			reactivate_fd(chan->fd, irq);
-		if (err == -EIO) {
-			if (chan->primary) {
-				if (tty != NULL)
-					tty_hangup(tty);
-				close_chan(chans, 1);
-				return;
-			}
-			else close_one_chan(chan, 1);
+	if (!chan || !chan->ops->read)
+		goto out;
+
+	do {
+		if (tty && !tty_buffer_request_room(tty, 1)) {
+			schedule_delayed_work(&line->task, 1);
+			goto out;
 		}
+		err = chan->ops->read(chan->fd, &c, chan->data);
+		if (err > 0)
+			tty_receive_char(tty, c);
+	} while (err > 0);
+
+	if (err == 0)
+		reactivate_fd(chan->fd, irq);
+	if (err == -EIO) {
+		if (chan->primary) {
+			if (tty != NULL)
+				tty_hangup(tty);
+			if (line->chan_out != chan)
+				close_one_chan(line->chan_out, 1);
+		}
+		close_one_chan(chan, 1);
+		if (chan->primary)
+			return;
 	}
  out:
 	if (tty)
diff --git a/arch/um/drivers/chan_user.h b/arch/um/drivers/chan_user.h
index 9b9ced85b703..6257b7a6e1af 100644
--- a/arch/um/drivers/chan_user.h
+++ b/arch/um/drivers/chan_user.h
@@ -14,8 +14,6 @@ struct chan_opts {
 	const int raw;
 };
 
-enum chan_init_pri { INIT_STATIC, INIT_ALL, INIT_ONE };
-
 struct chan_ops {
 	char *type;
 	void *(*init)(char *, int, const struct chan_opts *);
diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index c1cf2206b84b..4ab0d9c0911c 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -21,19 +21,10 @@ static irqreturn_t line_interrupt(int irq, void *data)
 	struct line *line = chan->line;
 
 	if (line)
-		chan_interrupt(&line->chan_list, &line->task, line->tty, irq);
+		chan_interrupt(line, line->tty, irq);
 	return IRQ_HANDLED;
 }
 
-static void line_timer_cb(struct work_struct *work)
-{
-	struct line *line = container_of(work, struct line, task.work);
-
-	if (!line->throttled)
-		chan_interrupt(&line->chan_list, &line->task, line->tty,
-			       line->driver->read_irq);
-}
-
 /*
  * Returns the free space inside the ring buffer of this line.
  *
@@ -145,7 +136,7 @@ static int flush_buffer(struct line *line)
 		/* line->buffer + LINE_BUFSIZE is the end of the buffer! */
 		count = line->buffer + LINE_BUFSIZE - line->head;
 
-		n = write_chan(&line->chan_list, line->head, count,
+		n = write_chan(line->chan_out, line->head, count,
 			       line->driver->write_irq);
 		if (n < 0)
 			return n;
@@ -162,7 +153,7 @@ static int flush_buffer(struct line *line)
 	}
 
 	count = line->tail - line->head;
-	n = write_chan(&line->chan_list, line->head, count,
+	n = write_chan(line->chan_out, line->head, count,
 		       line->driver->write_irq);
 
 	if (n < 0)
@@ -206,7 +197,7 @@ int line_write(struct tty_struct *tty, const unsigned char *buf, int len)
 	if (line->head != line->tail)
 		ret = buffer_data(line, buf, len);
 	else {
-		n = write_chan(&line->chan_list, buf, len,
+		n = write_chan(line->chan_out, buf, len,
 			       line->driver->write_irq);
 		if (n < 0) {
 			ret = n;
@@ -318,7 +309,7 @@ void line_throttle(struct tty_struct *tty)
 {
 	struct line *line = tty->driver_data;
 
-	deactivate_chan(&line->chan_list, line->driver->read_irq);
+	deactivate_chan(line->chan_in, line->driver->read_irq);
 	line->throttled = 1;
 }
 
@@ -327,8 +318,7 @@ 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);
+	chan_interrupt(line, tty, line->driver->read_irq);
 
 	/*
 	 * Maybe there is enough stuff pending that calling the interrupt
@@ -336,7 +326,7 @@ void line_unthrottle(struct tty_struct *tty)
 	 * again and we shouldn't turn the interrupt back on.
 	 */
 	if (!line->throttled)
-		reactivate_chan(&line->chan_list, line->driver->read_irq);
+		reactivate_chan(line->chan_in, line->driver->read_irq);
 }
 
 static irqreturn_t line_write_interrupt(int irq, void *data)
@@ -347,13 +337,14 @@ static irqreturn_t line_write_interrupt(int irq, void *data)
 	int err;
 
 	/*
-	 * Interrupts are disabled here because we registered the interrupt with
-	 * IRQF_DISABLED (see line_setup_irq).
+	 * Interrupts are disabled here because genirq keep irqs disabled when
+	 * calling the action handler.
 	 */
 
 	spin_lock(&line->lock);
 	err = flush_buffer(line);
 	if (err == 0) {
+		spin_unlock(&line->lock);
 		return IRQ_NONE;
 	} else if (err < 0) {
 		line->head = line->buffer;
@@ -371,7 +362,7 @@ static irqreturn_t line_write_interrupt(int irq, void *data)
 int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
 {
 	const struct line_driver *driver = line->driver;
-	int err = 0, flags = IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM;
+	int err = 0, flags = IRQF_SHARED | IRQF_SAMPLE_RANDOM;
 
 	if (input)
 		err = um_request_irq(driver->read_irq, fd, IRQ_READ,
@@ -383,7 +374,6 @@ int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
 		err = um_request_irq(driver->write_irq, fd, IRQ_WRITE,
 					line_write_interrupt, flags,
 					driver->write_irq_name, data);
-	line->have_irq = 1;
 	return err;
 }
 
@@ -409,7 +399,7 @@ int line_open(struct line *lines, struct tty_struct *tty)
 	struct line *line = &lines[tty->index];
 	int err = -ENODEV;
 
-	spin_lock(&line->count_lock);
+	mutex_lock(&line->count_lock);
 	if (!line->valid)
 		goto out_unlock;
 
@@ -421,25 +411,19 @@ int line_open(struct line *lines, struct tty_struct *tty)
 	tty->driver_data = line;
 	line->tty = tty;
 
-	spin_unlock(&line->count_lock);
 	err = enable_chan(line);
 	if (err) /* line_close() will be called by our caller */
-		return err;
-
-	INIT_DELAYED_WORK(&line->task, line_timer_cb);
+		goto out_unlock;
 
 	if (!line->sigio) {
-		chan_enable_winch(&line->chan_list, tty);
+		chan_enable_winch(line->chan_out, tty);
 		line->sigio = 1;
 	}
 
-	chan_window_size(&line->chan_list, &tty->winsize.ws_row,
+	chan_window_size(line, &tty->winsize.ws_row,
 			 &tty->winsize.ws_col);
-
-	return 0;
-
 out_unlock:
-	spin_unlock(&line->count_lock);
+	mutex_unlock(&line->count_lock);
 	return err;
 }
 
@@ -459,7 +443,7 @@ void line_close(struct tty_struct *tty, struct file * filp)
 	/* We ignore the error anyway! */
 	flush_buffer(line);
 
-	spin_lock(&line->count_lock);
+	mutex_lock(&line->count_lock);
 	BUG_ON(!line->valid);
 
 	if (--line->count)
@@ -468,17 +452,13 @@ void line_close(struct tty_struct *tty, struct file * filp)
 	line->tty = NULL;
 	tty->driver_data = NULL;
 
-	spin_unlock(&line->count_lock);
-
 	if (line->sigio) {
 		unregister_winch(tty);
 		line->sigio = 0;
 	}
 
-	return;
-
 out_unlock:
-	spin_unlock(&line->count_lock);
+	mutex_unlock(&line->count_lock);
 }
 
 void close_lines(struct line *lines, int nlines)
@@ -486,34 +466,60 @@ void close_lines(struct line *lines, int nlines)
 	int i;
 
 	for(i = 0; i < nlines; i++)
-		close_chan(&lines[i].chan_list, 0);
+		close_chan(&lines[i]);
 }
 
-static int setup_one_line(struct line *lines, int n, char *init, int init_prio,
-			  char **error_out)
+int setup_one_line(struct line *lines, int n, char *init,
+		   const struct chan_opts *opts, char **error_out)
 {
 	struct line *line = &lines[n];
+	struct tty_driver *driver = line->driver->driver;
 	int err = -EINVAL;
 
-	spin_lock(&line->count_lock);
+	mutex_lock(&line->count_lock);
 
 	if (line->count) {
 		*error_out = "Device is already open";
 		goto out;
 	}
 
-	if (line->init_pri <= init_prio) {
-		line->init_pri = init_prio;
-		if (!strcmp(init, "none"))
+	if (!strcmp(init, "none")) {
+		if (line->valid) {
+			line->valid = 0;
+			kfree(line->init_str);
+			tty_unregister_device(driver, n);
+			parse_chan_pair(NULL, line, n, opts, error_out);
+			err = 0;
+		}
+	} else {
+		char *new = kstrdup(init, GFP_KERNEL);
+		if (!new) {
+			*error_out = "Failed to allocate memory";
+			return -ENOMEM;
+		}
+		if (line->valid) {
+			tty_unregister_device(driver, n);
+			kfree(line->init_str);
+		}
+		line->init_str = new;
+		line->valid = 1;
+		err = parse_chan_pair(new, line, n, opts, error_out);
+		if (!err) {
+			struct device *d = tty_register_device(driver, n, NULL);
+			if (IS_ERR(d)) {
+				*error_out = "Failed to register device";
+				err = PTR_ERR(d);
+				parse_chan_pair(NULL, line, n, opts, error_out);
+			}
+		}
+		if (err) {
+			line->init_str = NULL;
 			line->valid = 0;
-		else {
-			line->init_str = init;
-			line->valid = 1;
+			kfree(new);
 		}
 	}
-	err = 0;
 out:
-	spin_unlock(&line->count_lock);
+	mutex_unlock(&line->count_lock);
 	return err;
 }
 
@@ -524,54 +530,43 @@ out:
  * @error_out is an error string in the case of failure;
  */
 
-int line_setup(struct line *lines, unsigned int num, char *init,
-	       char **error_out)
+int line_setup(char **conf, unsigned int num, char **def,
+	       char *init, char *name)
 {
-	int i, n, err;
-	char *end;
+	char *error;
 
 	if (*init == '=') {
 		/*
 		 * We said con=/ssl= instead of con#=, so we are configuring all
 		 * consoles at once.
 		 */
-		n = -1;
-	}
-	else {
-		n = simple_strtoul(init, &end, 0);
+		*def = init + 1;
+	} else {
+		char *end;
+		unsigned n = simple_strtoul(init, &end, 0);
+
 		if (*end != '=') {
-			*error_out = "Couldn't parse device number";
-			return -EINVAL;
+			error = "Couldn't parse device number";
+			goto out;
 		}
-		init = end;
-	}
-	init++;
-
-	if (n >= (signed int) num) {
-		*error_out = "Device number out of range";
-		return -EINVAL;
-	}
-	else if (n >= 0) {
-		err = setup_one_line(lines, n, init, INIT_ONE, error_out);
-		if (err)
-			return err;
-	}
-	else {
-		for(i = 0; i < num; i++) {
-			err = setup_one_line(lines, i, init, INIT_ALL,
-					     error_out);
-			if (err)
-				return err;
+		if (n >= num) {
+			error = "Device number out of range";
+			goto out;
 		}
+		conf[n] = end + 1;
 	}
-	return n == -1 ? num : n;
+	return 0;
+
+out:
+	printk(KERN_ERR "Failed to set up %s with "
+	       "configuration string \"%s\" : %s\n", name, init, error);
+	return -EINVAL;
 }
 
 int line_config(struct line *lines, unsigned int num, char *str,
 		const struct chan_opts *opts, char **error_out)
 {
-	struct line *line;
-	char *new;
+	char *end;
 	int n;
 
 	if (*str == '=') {
@@ -579,17 +574,17 @@ int line_config(struct line *lines, unsigned int num, char *str,
 		return -EINVAL;
 	}
 
-	new = kstrdup(str, GFP_KERNEL);
-	if (new == NULL) {
-		*error_out = "Failed to allocate memory";
-		return -ENOMEM;
+	n = simple_strtoul(str, &end, 0);
+	if (*end++ != '=') {
+		*error_out = "Couldn't parse device number";
+		return -EINVAL;
+	}
+	if (n >= num) {
+		*error_out = "Device number out of range";
+		return -EINVAL;
 	}
-	n = line_setup(lines, num, new, error_out);
-	if (n < 0)
-		return n;
 
-	line = &lines[n];
-	return parse_chan_pair(line->init_str, line, n, opts, error_out);
+	return setup_one_line(lines, n, end, opts, error_out);
 }
 
 int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
@@ -612,13 +607,13 @@ int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
 
 	line = &lines[dev];
 
-	spin_lock(&line->count_lock);
+	mutex_lock(&line->count_lock);
 	if (!line->valid)
 		CONFIG_CHUNK(str, size, n, "none", 1);
 	else if (line->tty == NULL)
 		CONFIG_CHUNK(str, size, n, line->init_str, 1);
-	else n = chan_config_string(&line->chan_list, str, size, error_out);
-	spin_unlock(&line->count_lock);
+	else n = chan_config_string(line, str, size, error_out);
+	mutex_unlock(&line->count_lock);
 
 	return n;
 }
@@ -640,25 +635,23 @@ int line_id(char **str, int *start_out, int *end_out)
 
 int line_remove(struct line *lines, unsigned int num, int n, char **error_out)
 {
-	int err;
-	char config[sizeof("conxxxx=none\0")];
-
-	sprintf(config, "%d=none", n);
-	err = line_setup(lines, num, config, error_out);
-	if (err >= 0)
-		err = 0;
-	return err;
+	if (n >= num) {
+		*error_out = "Device number out of range";
+		return -EINVAL;
+	}
+	return setup_one_line(lines, n, "none", NULL, error_out);
 }
 
-struct tty_driver *register_lines(struct line_driver *line_driver,
-				  const struct tty_operations *ops,
-				  struct line *lines, int nlines)
+int register_lines(struct line_driver *line_driver,
+		   const struct tty_operations *ops,
+		   struct line *lines, int nlines)
 {
-	int i;
 	struct tty_driver *driver = alloc_tty_driver(nlines);
+	int err;
+	int i;
 
 	if (!driver)
-		return NULL;
+		return -ENOMEM;
 
 	driver->driver_name = line_driver->name;
 	driver->name = line_driver->device_name;
@@ -666,54 +659,33 @@ struct tty_driver *register_lines(struct line_driver *line_driver,
 	driver->minor_start = line_driver->minor_start;
 	driver->type = line_driver->type;
 	driver->subtype = line_driver->subtype;
-	driver->flags = TTY_DRIVER_REAL_RAW;
+	driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
 	driver->init_termios = tty_std_termios;
+	
+	for (i = 0; i < nlines; i++) {
+		spin_lock_init(&lines[i].lock);
+		mutex_init(&lines[i].count_lock);
+		lines[i].driver = line_driver;
+		INIT_LIST_HEAD(&lines[i].chan_list);
+	}
 	tty_set_operations(driver, ops);
 
-	if (tty_register_driver(driver)) {
+	err = tty_register_driver(driver);
+	if (err) {
 		printk(KERN_ERR "register_lines : can't register %s driver\n",
 		       line_driver->name);
 		put_tty_driver(driver);
-		return NULL;
-	}
-
-	for(i = 0; i < nlines; i++) {
-		if (!lines[i].valid)
-			tty_unregister_device(driver, i);
+		return err;
 	}
 
+	line_driver->driver = driver;
 	mconsole_register_dev(&line_driver->mc);
-	return driver;
+	return 0;
 }
 
 static DEFINE_SPINLOCK(winch_handler_lock);
 static LIST_HEAD(winch_handlers);
 
-void lines_init(struct line *lines, int nlines, struct chan_opts *opts)
-{
-	struct line *line;
-	char *error;
-	int i;
-
-	for(i = 0; i < nlines; i++) {
-		line = &lines[i];
-		INIT_LIST_HEAD(&line->chan_list);
-
-		if (line->init_str == NULL)
-			continue;
-
-		line->init_str = kstrdup(line->init_str, GFP_KERNEL);
-		if (line->init_str == NULL)
-			printk(KERN_ERR "lines_init - kstrdup returned NULL\n");
-
-		if (parse_chan_pair(line->init_str, line, i, opts, &error)) {
-			printk(KERN_ERR "parse_chan_pair failed for "
-			       "device %d : %s\n", i, error);
-			line->valid = 0;
-		}
-	}
-}
-
 struct winch {
 	struct list_head list;
 	int fd;
@@ -777,7 +749,7 @@ static irqreturn_t winch_interrupt(int irq, void *data)
 	if (tty != NULL) {
 		line = tty->driver_data;
 		if (line != NULL) {
-			chan_window_size(&line->chan_list, &tty->winsize.ws_row,
+			chan_window_size(line, &tty->winsize.ws_row,
 					 &tty->winsize.ws_col);
 			kill_pgrp(tty->pgrp, SIGWINCH, 1);
 		}
@@ -807,7 +779,7 @@ void register_winch_irq(int fd, int tty_fd, int pid, struct tty_struct *tty,
 				   .stack	= stack });
 
 	if (um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
-			   IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
+			   IRQF_SHARED | IRQF_SAMPLE_RANDOM,
 			   "winch", winch) < 0) {
 		printk(KERN_ERR "register_winch_irq - failed to register "
 		       "IRQ\n");
diff --git a/arch/um/drivers/line.h b/arch/um/drivers/line.h
index 63df3ca02ac2..0a1834719dba 100644
--- a/arch/um/drivers/line.h
+++ b/arch/um/drivers/line.h
@@ -15,7 +15,7 @@
 #include "chan_user.h"
 #include "mconsole_kern.h"
 
-/* There's only one modifiable field in this - .mc.list */
+/* There's only two modifiable fields in this - .mc.list and .driver */
 struct line_driver {
 	const char *name;
 	const char *device_name;
@@ -28,17 +28,18 @@ struct line_driver {
 	const int write_irq;
 	const char *write_irq_name;
 	struct mc_device mc;
+	struct tty_driver *driver;
 };
 
 struct line {
 	struct tty_struct *tty;
-	spinlock_t count_lock;
+	struct mutex count_lock;
 	unsigned long count;
 	int valid;
 
 	char *init_str;
-	int init_pri;
 	struct list_head chan_list;
+	struct chan *chan_in, *chan_out;
 
 	/*This lock is actually, mostly, local to*/
 	spinlock_t lock;
@@ -55,21 +56,12 @@ struct line {
 	int sigio;
 	struct delayed_work task;
 	const struct line_driver *driver;
-	int have_irq;
 };
 
-#define LINE_INIT(str, d) \
-	{ .count_lock =	__SPIN_LOCK_UNLOCKED((str).count_lock), \
-	  .init_str =	str,	\
-	  .init_pri =	INIT_STATIC, \
-	  .valid =	1, \
-	  .lock =	__SPIN_LOCK_UNLOCKED((str).lock), \
-	  .driver =	d }
-
 extern void line_close(struct tty_struct *tty, struct file * filp);
 extern int line_open(struct line *lines, struct tty_struct *tty);
-extern int line_setup(struct line *lines, unsigned int sizeof_lines,
-		      char *init, char **error_out);
+extern int line_setup(char **conf, unsigned nlines, char **def,
+		      char *init, char *name);
 extern int line_write(struct tty_struct *tty, const unsigned char *buf,
 		      int len);
 extern int line_put_char(struct tty_struct *tty, unsigned char ch);
@@ -87,10 +79,11 @@ extern char *add_xterm_umid(char *base);
 extern int line_setup_irq(int fd, int input, int output, struct line *line,
 			  void *data);
 extern void line_close_chan(struct line *line);
-extern struct tty_driver *register_lines(struct line_driver *line_driver,
-					 const struct tty_operations *driver,
-					 struct line *lines, int nlines);
-extern void lines_init(struct line *lines, int nlines, struct chan_opts *opts);
+extern int register_lines(struct line_driver *line_driver,
+			  const struct tty_operations *driver,
+			  struct line *lines, int nlines);
+extern int setup_one_line(struct line *lines, int n, char *init,
+			  const struct chan_opts *opts, char **error_out);
 extern void close_lines(struct line *lines, int nlines);
 
 extern int line_config(struct line *lines, unsigned int sizeof_lines,
diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index c70e047eed72..e672bd6d43e3 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -773,7 +773,7 @@ static int __init mconsole_init(void)
 	register_reboot_notifier(&reboot_notifier);
 
 	err = um_request_irq(MCONSOLE_IRQ, sock, IRQ_READ, mconsole_interrupt,
-			     IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
+			     IRQF_SHARED | IRQF_SAMPLE_RANDOM,
 			     "mconsole", (void *)sock);
 	if (err) {
 		printk(KERN_ERR "Failed to get IRQ for management console\n");
diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c
index d2996183e584..95f4416e6d9f 100644
--- a/arch/um/drivers/net_kern.c
+++ b/arch/um/drivers/net_kern.c
@@ -161,7 +161,7 @@ static int uml_net_open(struct net_device *dev)
 	}
 
 	err = um_request_irq(dev->irq, lp->fd, IRQ_READ, uml_net_interrupt,
-			     IRQF_DISABLED | IRQF_SHARED, dev->name, dev);
+			     IRQF_SHARED, dev->name, dev);
 	if (err != 0) {
 		printk(KERN_ERR "uml_net_open: failed to get irq(%d)\n", err);
 		err = -ENETUNREACH;
diff --git a/arch/um/drivers/port_kern.c b/arch/um/drivers/port_kern.c
index a11573be0961..e31680e662a4 100644
--- a/arch/um/drivers/port_kern.c
+++ b/arch/um/drivers/port_kern.c
@@ -100,7 +100,7 @@ static int port_accept(struct port_list *port)
 		  .port 	= port });
 
 	if (um_request_irq(TELNETD_IRQ, socket[0], IRQ_READ, pipe_interrupt,
-			  IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
+			  IRQF_SHARED | IRQF_SAMPLE_RANDOM,
 			  "telnetd", conn)) {
 		printk(KERN_ERR "port_accept : failed to get IRQ for "
 		       "telnetd\n");
@@ -184,7 +184,7 @@ void *port_data(int port_num)
 	}
 
 	if (um_request_irq(ACCEPT_IRQ, fd, IRQ_READ, port_interrupt,
-			  IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
+			  IRQF_SHARED | IRQF_SAMPLE_RANDOM,
 			  "port", port)) {
 		printk(KERN_ERR "Failed to get IRQ for port %d\n", port_num);
 		goto out_close;
diff --git a/arch/um/drivers/random.c b/arch/um/drivers/random.c
index 981085a93f30..b25296e6218a 100644
--- a/arch/um/drivers/random.c
+++ b/arch/um/drivers/random.c
@@ -131,7 +131,7 @@ static int __init rng_init (void)
 	random_fd = err;
 
 	err = um_request_irq(RANDOM_IRQ, random_fd, IRQ_READ, random_interrupt,
-			     IRQF_DISABLED | IRQF_SAMPLE_RANDOM, "random",
+			     IRQF_SAMPLE_RANDOM, "random",
 			     NULL);
 	if (err)
 		goto err_out_cleanup_hw;
diff --git a/arch/um/drivers/ssl.c b/arch/um/drivers/ssl.c
index 9d8c20af6f80..e09801a1327b 100644
--- a/arch/um/drivers/ssl.c
+++ b/arch/um/drivers/ssl.c
@@ -20,12 +20,6 @@
 
 static const int ssl_version = 1;
 
-/* Referenced only by tty_driver below - presumably it's locked correctly
- * by the tty driver.
- */
-
-static struct tty_driver *ssl_driver;
-
 #define NR_PORTS 64
 
 static void ssl_announce(char *dev_name, int dev)
@@ -71,8 +65,9 @@ static struct line_driver driver = {
 /* The array is initialized by line_init, at initcall time.  The
  * elements are locked individually as needed.
  */
-static struct line serial_lines[NR_PORTS] =
-	{ [0 ... NR_PORTS - 1] = LINE_INIT(CONFIG_SSL_CHAN, &driver) };
+static char *conf[NR_PORTS];
+static char *def_conf = CONFIG_SSL_CHAN;
+static struct line serial_lines[NR_PORTS];
 
 static int ssl_config(char *str, char **error_out)
 {
@@ -156,14 +151,14 @@ static void ssl_console_write(struct console *c, const char *string,
 	unsigned long flags;
 
 	spin_lock_irqsave(&line->lock, flags);
-	console_write_chan(&line->chan_list, string, len);
+	console_write_chan(line->chan_out, string, len);
 	spin_unlock_irqrestore(&line->lock, flags);
 }
 
 static struct tty_driver *ssl_console_device(struct console *c, int *index)
 {
 	*index = c->index;
-	return ssl_driver;
+	return driver.driver;
 }
 
 static int ssl_console_setup(struct console *co, char *options)
@@ -186,17 +181,30 @@ static struct console ssl_cons = {
 static int ssl_init(void)
 {
 	char *new_title;
+	int err;
+	int i;
 
 	printk(KERN_INFO "Initializing software serial port version %d\n",
 	       ssl_version);
-	ssl_driver = register_lines(&driver, &ssl_ops, serial_lines,
+
+	err = register_lines(&driver, &ssl_ops, serial_lines,
 				    ARRAY_SIZE(serial_lines));
+	if (err)
+		return err;
 
 	new_title = add_xterm_umid(opts.xterm_title);
 	if (new_title != NULL)
 		opts.xterm_title = new_title;
 
-	lines_init(serial_lines, ARRAY_SIZE(serial_lines), &opts);
+	for (i = 0; i < NR_PORTS; i++) {
+		char *error;
+		char *s = conf[i];
+		if (!s)
+			s = def_conf;
+		if (setup_one_line(serial_lines, i, s, &opts, &error))
+			printk(KERN_ERR "setup_one_line failed for "
+			       "device %d : %s\n", i, error);
+	}
 
 	ssl_init_done = 1;
 	register_console(&ssl_cons);
@@ -214,14 +222,7 @@ __uml_exitcall(ssl_exit);
 
 static int ssl_chan_setup(char *str)
 {
-	char *error;
-	int ret;
-
-	ret = line_setup(serial_lines, ARRAY_SIZE(serial_lines), str, &error);
-	if(ret < 0)
-		printk(KERN_ERR "Failed to set up serial line with "
-		       "configuration string \"%s\" : %s\n", str, error);
-
+	line_setup(conf, NR_PORTS, &def_conf, str, "serial line");
 	return 1;
 }
 
diff --git a/arch/um/drivers/stdio_console.c b/arch/um/drivers/stdio_console.c
index 088776f01908..7663541c372e 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,
@@ -76,9 +70,9 @@ static struct line_driver driver = {
 /* The array is initialized by line_init, at initcall time.  The
  * elements are locked individually as needed.
  */
-static struct line vts[MAX_TTYS] = { LINE_INIT(CONFIG_CON_ZERO_CHAN, &driver),
-				     [ 1 ... MAX_TTYS - 1 ] =
-				     LINE_INIT(CONFIG_CON_CHAN, &driver) };
+static char *vt_conf[MAX_TTYS];
+static char *def_conf;
+static struct line vts[MAX_TTYS];
 
 static int con_config(char *str, char **error_out)
 {
@@ -130,14 +124,14 @@ static void uml_console_write(struct console *console, const char *string,
 	unsigned long flags;
 
 	spin_lock_irqsave(&line->lock, flags);
-	console_write_chan(&line->chan_list, string, len);
+	console_write_chan(line->chan_out, string, len);
 	spin_unlock_irqrestore(&line->lock, flags);
 }
 
 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)
@@ -160,18 +154,31 @@ static struct console stdiocons = {
 static int stdio_init(void)
 {
 	char *new_title;
+	int err;
+	int i;
 
-	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);
 	if(new_title != NULL)
 		opts.xterm_title = new_title;
 
-	lines_init(vts, ARRAY_SIZE(vts), &opts);
+	for (i = 0; i < MAX_TTYS; i++) {
+		char *error;
+		char *s = vt_conf[i];
+		if (!s)
+			s = def_conf;
+		if (!s)
+			s = i ? CONFIG_CON_CHAN : CONFIG_CON_ZERO_CHAN;
+		if (setup_one_line(vts, i, s, &opts, &error))
+			printk(KERN_ERR "setup_one_line failed for "
+			       "device %d : %s\n", i, error);
+	}
 
 	con_init_done = 1;
 	register_console(&stdiocons);
@@ -189,14 +196,7 @@ __uml_exitcall(console_exit);
 
 static int console_chan_setup(char *str)
 {
-	char *error;
-	int ret;
-
-	ret = line_setup(vts, ARRAY_SIZE(vts), str, &error);
-	if(ret < 0)
-		printk(KERN_ERR "Failed to set up console with "
-		       "configuration string \"%s\" : %s\n", str, error);
-
+	line_setup(vt_conf, MAX_TTYS, &def_conf, str, "console");
 	return 1;
 }
 __setup("con", console_chan_setup);
diff --git a/arch/um/drivers/ubd_user.h b/arch/um/drivers/ubd.h
index 3845051f1b10..3845051f1b10 100644
--- a/arch/um/drivers/ubd_user.h
+++ b/arch/um/drivers/ubd.h
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 944453a3ec99..20505cafa299 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -19,40 +19,26 @@
 
 #define UBD_SHIFT 4
 
-#include "linux/kernel.h"
-#include "linux/module.h"
-#include "linux/blkdev.h"
-#include "linux/ata.h"
-#include "linux/hdreg.h"
-#include "linux/init.h"
-#include "linux/cdrom.h"
-#include "linux/proc_fs.h"
-#include "linux/seq_file.h"
-#include "linux/ctype.h"
-#include "linux/capability.h"
-#include "linux/mm.h"
-#include "linux/slab.h"
-#include "linux/vmalloc.h"
-#include "linux/mutex.h"
-#include "linux/blkpg.h"
-#include "linux/genhd.h"
-#include "linux/spinlock.h"
-#include "linux/platform_device.h"
-#include "linux/scatterlist.h"
-#include "asm/segment.h"
-#include "asm/uaccess.h"
-#include "asm/irq.h"
-#include "asm/types.h"
-#include "asm/tlbflush.h"
-#include "mem_user.h"
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/blkdev.h>
+#include <linux/ata.h>
+#include <linux/hdreg.h>
+#include <linux/cdrom.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/ctype.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/platform_device.h>
+#include <linux/scatterlist.h>
+#include <asm/tlbflush.h>
 #include "kern_util.h"
 #include "mconsole_kern.h"
 #include "init.h"
-#include "irq_user.h"
 #include "irq_kern.h"
-#include "ubd_user.h"
+#include "ubd.h"
 #include "os.h"
-#include "mem.h"
 #include "cow.h"
 
 enum ubd_req { UBD_READ, UBD_WRITE };
@@ -1115,7 +1101,7 @@ static int __init ubd_driver_init(void){
 		return 0;
 	}
 	err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr,
-			     IRQF_DISABLED, "ubd", ubd_devs);
+			     0, "ubd", ubd_devs);
 	if(err != 0)
 		printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err);
 	return 0;
diff --git a/arch/um/drivers/ubd_user.c b/arch/um/drivers/ubd_user.c
index 007b94d97726..ffe02c431dea 100644
--- a/arch/um/drivers/ubd_user.c
+++ b/arch/um/drivers/ubd_user.c
@@ -15,14 +15,12 @@
 #include <sys/socket.h>
 #include <sys/mman.h>
 #include <sys/param.h>
-#include "asm/types.h"
-#include "ubd_user.h"
-#include "os.h"
-#include "cow.h"
-
 #include <endian.h>
 #include <byteswap.h>
 
+#include "ubd.h"
+#include "os.h"
+
 void ignore_sigwinch_sig(void)
 {
 	signal(SIGWINCH, SIG_IGN);
diff --git a/arch/um/drivers/xterm_kern.c b/arch/um/drivers/xterm_kern.c
index b646bccef37a..8bd130f0bda3 100644
--- a/arch/um/drivers/xterm_kern.c
+++ b/arch/um/drivers/xterm_kern.c
@@ -50,7 +50,7 @@ int xterm_fd(int socket, int *pid_out)
 	init_completion(&data->ready);
 
 	err = um_request_irq(XTERM_IRQ, socket, IRQ_READ, xterm_interrupt,
-			     IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
+			     IRQF_SHARED | IRQF_SAMPLE_RANDOM,
 			     "xterm", data);
 	if (err) {
 		printk(KERN_ERR "xterm_fd : failed to get IRQ for xterm, "