diff options
Diffstat (limited to 'drivers/tty/tty_buffer.c')
| -rw-r--r-- | drivers/tty/tty_buffer.c | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c index 4cf263d7dffc..5a3fa8913880 100644 --- a/drivers/tty/tty_buffer.c +++ b/drivers/tty/tty_buffer.c @@ -291,12 +291,11 @@ static int __tty_buffer_request_room(struct tty_port *port, size_t size, n->flags = flags; buf->tail = n; b->commit = b->used; - /* paired w/ barrier in flush_to_ldisc(); ensures the + /* paired w/ acquire in flush_to_ldisc(); ensures the * latest commit value can be read before the head is * advanced to the next buffer */ - smp_wmb(); - b->next = n; + smp_store_release(&b->next, n); } else if (change) size = 0; else @@ -445,7 +444,6 @@ receive_buf(struct tty_struct *tty, struct tty_buffer *head, int count) if (count) disc->ops->receive_buf(tty, p, f, count); } - head->read += count; return count; } @@ -488,12 +486,11 @@ static void flush_to_ldisc(struct work_struct *work) if (atomic_read(&buf->priority)) break; - next = head->next; - /* paired w/ barrier in __tty_buffer_request_room(); + /* paired w/ release in __tty_buffer_request_room(); * ensures commit value read is not stale if the head * is advancing to the next buffer */ - smp_rmb(); + next = smp_load_acquire(&head->next); count = head->commit - head->read; if (!count) { if (next == NULL) { @@ -508,6 +505,7 @@ static void flush_to_ldisc(struct work_struct *work) count = receive_buf(tty, head, count); if (!count) break; + head->read += count; } mutex_unlock(&buf->lock); |