diff options
Diffstat (limited to 'drivers/char/tty_io.c')
| -rw-r--r-- | drivers/char/tty_io.c | 75 |
1 files changed, 33 insertions, 42 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index 8b2a59969868..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) |