diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c index 94f9e3a38412..0ff7fda0742f 100644 --- a/drivers/tty/hvc/hvc_console.c +++ b/drivers/tty/hvc/hvc_console.c @@ -190,7 +190,7 @@ static struct tty_driver *hvc_console_device(struct console *c, int *index) return hvc_driver; } -static int __init hvc_console_setup(struct console *co, char *options) +static int hvc_console_setup(struct console *co, char *options) { if (co->index < 0 || co->index >= MAX_NR_HVC_CONSOLES) return -ENODEV; diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index 41fe8a047d37..fe9d129c8735 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -2353,8 +2353,12 @@ static ssize_t n_tty_write(struct tty_struct *tty, struct file *file, if (tty->ops->flush_chars) tty->ops->flush_chars(tty); } else { + struct n_tty_data *ldata = tty->disc_data; + while (nr > 0) { + mutex_lock(&ldata->output_lock); c = tty->ops->write(tty, b, nr); + mutex_unlock(&ldata->output_lock); if (c < 0) { retval = c; goto break_out; diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index 0e1bf8858431..2d4bd3929e50 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -555,7 +555,7 @@ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep) */ if ((p->port.type == PORT_XR17V35X) || (p->port.type == PORT_XR17D15X)) { - serial_out(p, UART_EXAR_SLEEP, 0xff); + serial_out(p, UART_EXAR_SLEEP, sleep ? 0xff : 0); return; } diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c index f1d30f6945af..cf78d1985cd8 100644 --- a/drivers/tty/tty_buffer.c +++ b/drivers/tty/tty_buffer.c @@ -255,16 +255,15 @@ static int __tty_buffer_request_room(struct tty_port *port, size_t size, if (change || left < size) { /* This is the slow path - looking for new buffers to use */ if ((n = tty_buffer_alloc(port, size)) != NULL) { - unsigned long iflags; - n->flags = flags; buf->tail = n; - - spin_lock_irqsave(&buf->flush_lock, iflags); b->commit = b->used; + /* paired w/ barrier 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; - spin_unlock_irqrestore(&buf->flush_lock, iflags); - } else if (change) size = 0; else @@ -448,27 +447,28 @@ static void flush_to_ldisc(struct work_struct *work) mutex_lock(&buf->lock); while (1) { - unsigned long flags; struct tty_buffer *head = buf->head; + struct tty_buffer *next; int count; /* Ldisc or user is trying to gain exclusive access */ if (atomic_read(&buf->priority)) break; - spin_lock_irqsave(&buf->flush_lock, flags); + next = head->next; + /* paired w/ barrier in __tty_buffer_request_room(); + * ensures commit value read is not stale if the head + * is advancing to the next buffer + */ + smp_rmb(); count = head->commit - head->read; if (!count) { - if (head->next == NULL) { - spin_unlock_irqrestore(&buf->flush_lock, flags); + if (next == NULL) break; - } - buf->head = head->next; - spin_unlock_irqrestore(&buf->flush_lock, flags); + buf->head = next; tty_buffer_free(port, head); continue; } - spin_unlock_irqrestore(&buf->flush_lock, flags); count = receive_buf(tty, head, count); if (!count) @@ -523,7 +523,6 @@ void tty_buffer_init(struct tty_port *port) struct tty_bufhead *buf = &port->buf; mutex_init(&buf->lock); - spin_lock_init(&buf->flush_lock); tty_buffer_reset(&buf->sentinel, 0); buf->head = &buf->sentinel; buf->tail = &buf->sentinel; diff --git a/include/linux/tty.h b/include/linux/tty.h index 036cccd80d9f..1c3316a47d7e 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -61,7 +61,6 @@ struct tty_bufhead { struct tty_buffer *head; /* Queue head */ struct work_struct work; struct mutex lock; - spinlock_t flush_lock; atomic_t priority; struct tty_buffer sentinel; struct llist_head free; /* Free queue head */