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path: root/drivers/char/tty_io.c
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Diffstat (limited to 'drivers/char/tty_io.c')
-rw-r--r--drivers/char/tty_io.c86
1 files changed, 40 insertions, 46 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index a88b94a82b14..8d19f7281f0b 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -267,7 +267,6 @@ static struct tty_buffer *tty_buffer_alloc(size_t size)
p->used = 0;
p->size = size;
p->next = NULL;
- p->active = 0;
p->commit = 0;
p->read = 0;
p->char_buf_ptr = (char *)(p->data);
@@ -327,10 +326,9 @@ int tty_buffer_request_room(struct tty_struct *tty, size_t size)
/* OPTIMISATION: We could keep a per tty "zero" sized buffer to
remove this conditional if its worth it. This would be invisible
to the callers */
- if ((b = tty->buf.tail) != NULL) {
+ if ((b = tty->buf.tail) != NULL)
left = b->size - b->used;
- b->active = 1;
- } else
+ else
left = 0;
if (left < size) {
@@ -338,12 +336,10 @@ int tty_buffer_request_room(struct tty_struct *tty, size_t size)
if ((n = tty_buffer_find(tty, size)) != NULL) {
if (b != NULL) {
b->next = n;
- b->active = 0;
b->commit = b->used;
} else
tty->buf.head = n;
tty->buf.tail = n;
- n->active = 1;
} else
size = left;
}
@@ -404,10 +400,8 @@ void tty_schedule_flip(struct tty_struct *tty)
{
unsigned long flags;
spin_lock_irqsave(&tty->buf.lock, flags);
- if (tty->buf.tail != NULL) {
- tty->buf.tail->active = 0;
+ if (tty->buf.tail != NULL)
tty->buf.tail->commit = tty->buf.tail->used;
- }
spin_unlock_irqrestore(&tty->buf.lock, flags);
schedule_delayed_work(&tty->buf.work, 1);
}
@@ -784,11 +778,8 @@ restart:
}
clear_bit(TTY_LDISC, &tty->flags);
- clear_bit(TTY_DONT_FLIP, &tty->flags);
- if (o_tty) {
+ if (o_tty)
clear_bit(TTY_LDISC, &o_tty->flags);
- clear_bit(TTY_DONT_FLIP, &o_tty->flags);
- }
spin_unlock_irqrestore(&tty_ldisc_lock, flags);
/*
@@ -1955,7 +1946,6 @@ static void release_dev(struct file * filp)
* race with the set_ldisc code path.
*/
clear_bit(TTY_LDISC, &tty->flags);
- clear_bit(TTY_DONT_FLIP, &tty->flags);
cancel_delayed_work(&tty->buf.work);
/*
@@ -2621,10 +2611,9 @@ int tty_ioctl(struct inode * inode, struct file * file,
tty->driver->break_ctl(tty, 0);
return 0;
case TCSBRK: /* SVID version: non-zero arg --> no break */
- /*
- * XXX is the above comment correct, or the
- * code below correct? Is this ioctl used at
- * all by anyone?
+ /* non-zero arg means wait for all output data
+ * to be sent (performed above) but don't send break.
+ * This is used by the tcdrain() termios function.
*/
if (!arg)
return send_break(tty, 250);
@@ -2776,8 +2765,7 @@ static void flush_to_ldisc(void *private_)
struct tty_struct *tty = (struct tty_struct *) private_;
unsigned long flags;
struct tty_ldisc *disc;
- struct tty_buffer *tbuf;
- int count;
+ struct tty_buffer *tbuf, *head;
char *char_buf;
unsigned char *flag_buf;
@@ -2785,32 +2773,37 @@ static void flush_to_ldisc(void *private_)
if (disc == NULL) /* !TTY_LDISC */
return;
- if (test_bit(TTY_DONT_FLIP, &tty->flags)) {
- /*
- * Do it after the next timer tick:
- */
- schedule_delayed_work(&tty->buf.work, 1);
- goto out;
- }
spin_lock_irqsave(&tty->buf.lock, flags);
- while((tbuf = tty->buf.head) != NULL) {
- while ((count = tbuf->commit - tbuf->read) != 0) {
- char_buf = tbuf->char_buf_ptr + tbuf->read;
- flag_buf = tbuf->flag_buf_ptr + tbuf->read;
- tbuf->read += count;
+ head = tty->buf.head;
+ if (head != NULL) {
+ tty->buf.head = NULL;
+ for (;;) {
+ int count = head->commit - head->read;
+ if (!count) {
+ if (head->next == NULL)
+ break;
+ tbuf = head;
+ head = head->next;
+ tty_buffer_free(tty, tbuf);
+ continue;
+ }
+ if (!tty->receive_room) {
+ schedule_delayed_work(&tty->buf.work, 1);
+ break;
+ }
+ if (count > tty->receive_room)
+ count = tty->receive_room;
+ char_buf = head->char_buf_ptr + head->read;
+ flag_buf = head->flag_buf_ptr + head->read;
+ head->read += count;
spin_unlock_irqrestore(&tty->buf.lock, flags);
disc->receive_buf(tty, char_buf, flag_buf, count);
spin_lock_irqsave(&tty->buf.lock, flags);
}
- if (tbuf->active)
- break;
- tty->buf.head = tbuf->next;
- if (tty->buf.head == NULL)
- tty->buf.tail = NULL;
- tty_buffer_free(tty, tbuf);
+ tty->buf.head = head;
}
spin_unlock_irqrestore(&tty->buf.lock, flags);
-out:
+
tty_ldisc_deref(disc);
}
@@ -2903,10 +2896,8 @@ void tty_flip_buffer_push(struct tty_struct *tty)
{
unsigned long flags;
spin_lock_irqsave(&tty->buf.lock, flags);
- if (tty->buf.tail != NULL) {
- tty->buf.tail->active = 0;
+ if (tty->buf.tail != NULL)
tty->buf.tail->commit = tty->buf.tail->used;
- }
spin_unlock_irqrestore(&tty->buf.lock, flags);
if (tty->low_latency)
@@ -2961,12 +2952,14 @@ static struct class *tty_class;
* This field is optional, if there is no known struct device for this
* tty device it can be set to NULL safely.
*
+ * Returns a pointer to the class device (or ERR_PTR(-EFOO) on error).
+ *
* This call is required to be made to register an individual tty device if
* the tty driver's flags have the TTY_DRIVER_NO_DEVFS bit set. If that
* bit is not set, this function should not be called.
*/
-void tty_register_device(struct tty_driver *driver, unsigned index,
- struct device *device)
+struct class_device *tty_register_device(struct tty_driver *driver,
+ unsigned index, struct device *device)
{
char name[64];
dev_t dev = MKDEV(driver->major, driver->minor_start) + index;
@@ -2974,7 +2967,7 @@ void tty_register_device(struct tty_driver *driver, unsigned index,
if (index >= driver->num) {
printk(KERN_ERR "Attempt to register invalid tty line number "
" (%d).\n", index);
- return;
+ return ERR_PTR(-EINVAL);
}
devfs_mk_cdev(dev, S_IFCHR | S_IRUSR | S_IWUSR,
@@ -2984,7 +2977,8 @@ void tty_register_device(struct tty_driver *driver, unsigned index,
pty_line_name(driver, index, name);
else
tty_line_name(driver, index, name);
- class_device_create(tty_class, NULL, dev, device, "%s", name);
+
+ return class_device_create(tty_class, NULL, dev, device, "%s", name);
}
/**
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-23 03:21:26 +0300