[PATCH] new tty buffering access fix

Fix typos in new tty buffering that incorrectly
access and update buffers in pending queue.

Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 1eda82b..eb8b5be 100644 (file)
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -312,7 +312,7 @@ static struct tty_buffer *tty_buffer_find(struct tty_struct *tty, size_t size)
 
 int tty_buffer_request_room(struct tty_struct *tty, size_t size)
 {
-       struct tty_buffer *b = tty->buf.head, *n;
+       struct tty_buffer *b = tty->buf.tail, *n;
        int left = 0;
 
        /* OPTIMISATION: We could keep a per tty "zero" sized buffer to
@@ -326,7 +326,6 @@ int tty_buffer_request_room(struct tty_struct *tty, size_t size)
        n = tty_buffer_find(tty, size);
        if(n == NULL)
                return left;
-       n->next = b;
        if(b != NULL)
                b->next = n;
        else
@@ -2751,6 +2750,8 @@ static void flush_to_ldisc(void *private_)
        spin_lock_irqsave(&tty->read_lock, flags);
        while((tbuf = tty->buf.head) != NULL) {
                tty->buf.head = tbuf->next;
+               if (tty->buf.head == NULL)
+                       tty->buf.tail = NULL;
                spin_unlock_irqrestore(&tty->read_lock, flags);
                /* printk("Process buffer %p for %d\n", tbuf, tbuf->used); */
                disc->receive_buf(tty, tbuf->char_buf_ptr,
@@ -2759,7 +2760,6 @@ static void flush_to_ldisc(void *private_)
                spin_lock_irqsave(&tty->read_lock, flags);
                tty_buffer_free(tty, tbuf);
        }
-       tty->buf.tail = NULL;
        spin_unlock_irqrestore(&tty->read_lock, flags);
 out:
        tty_ldisc_deref(disc);