diff --git a/Documentation/serial/tty.txt b/Documentation/serial/tty.txt
index 1e52d67d0abf5c8ccb86b6aa5d1170f509d73132..dbe6623fed1c286bd49277486492b2960428eff6 100644
--- a/Documentation/serial/tty.txt
+++ b/Documentation/serial/tty.txt
@@ -198,6 +198,9 @@ TTY_IO_ERROR If set, causes all subsequent userspace read/write
TTY_OTHER_CLOSED Device is a pty and the other side has closed.
+TTY_OTHER_DONE Device is a pty and the other side has closed and
+ all pending input processing has been completed.
+
TTY_NO_WRITE_SPLIT Prevent driver from splitting up writes into
smaller chunks.
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 91abc00aa833b8493fe721e05024cd8368e23aa6..2c34c3249972de85f650d34fa0b25448efba3686 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -3170,7 +3170,7 @@ static int gsmtty_break_ctl(struct tty_struct *tty, int state)
return gsmtty_modem_update(dlci, encode);
}
-static void gsmtty_remove(struct tty_driver *driver, struct tty_struct *tty)
+static void gsmtty_cleanup(struct tty_struct *tty)
{
struct gsm_dlci *dlci = tty->driver_data;
struct gsm_mux *gsm = dlci->gsm;
@@ -3178,7 +3178,6 @@ static void gsmtty_remove(struct tty_driver *driver, struct tty_struct *tty)
dlci_put(dlci);
dlci_put(gsm->dlci[0]);
mux_put(gsm);
- driver->ttys[tty->index] = NULL;
}
/* Virtual ttys for the demux */
@@ -3199,7 +3198,7 @@ static const struct tty_operations gsmtty_ops = {
.tiocmget = gsmtty_tiocmget,
.tiocmset = gsmtty_tiocmset,
.break_ctl = gsmtty_break_ctl,
- .remove = gsmtty_remove,
+ .cleanup = gsmtty_cleanup,
};
diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c
index 644ddb841d9f54085bb82a903034af5aaf42de45..bbc4ce66c2c18dd30fb10b80f955a4f4565225c5 100644
--- a/drivers/tty/n_hdlc.c
+++ b/drivers/tty/n_hdlc.c
@@ -600,7 +600,7 @@ static ssize_t n_hdlc_tty_read(struct tty_struct *tty, struct file *file,
add_wait_queue(&tty->read_wait, &wait);
for (;;) {
- if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
+ if (test_bit(TTY_OTHER_DONE, &tty->flags)) {
ret = -EIO;
break;
}
@@ -828,7 +828,7 @@ static unsigned int n_hdlc_tty_poll(struct tty_struct *tty, struct file *filp,
/* set bits for operations that won't block */
if (n_hdlc->rx_buf_list.head)
mask |= POLLIN | POLLRDNORM; /* readable */
- if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
+ if (test_bit(TTY_OTHER_DONE, &tty->flags))
mask |= POLLHUP;
if (tty_hung_up_p(filp))
mask |= POLLHUP;
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index cf6e0f2e1331fd46310a6834d99896e2b943ea19..cc57a3a6b02b348df95c827fd2c770e59ffca155 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -1949,6 +1949,18 @@ static inline int input_available_p(struct tty_struct *tty, int poll)
return ldata->commit_head - ldata->read_tail >= amt;
}
+static inline int check_other_done(struct tty_struct *tty)
+{
+ int done = test_bit(TTY_OTHER_DONE, &tty->flags);
+ if (done) {
+ /* paired with cmpxchg() in check_other_closed(); ensures
+ * read buffer head index is not stale
+ */
+ smp_mb__after_atomic();
+ }
+ return done;
+}
+
/**
* copy_from_read_buf - copy read data directly
* @tty: terminal device
@@ -2167,7 +2179,7 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
struct n_tty_data *ldata = tty->disc_data;
unsigned char __user *b = buf;
DEFINE_WAIT_FUNC(wait, woken_wake_function);
- int c;
+ int c, done;
int minimum, time;
ssize_t retval = 0;
long timeout;
@@ -2235,8 +2247,10 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
((minimum - (b - buf)) >= 1))
ldata->minimum_to_wake = (minimum - (b - buf));
+ done = check_other_done(tty);
+
if (!input_available_p(tty, 0)) {
- if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
+ if (done) {
retval = -EIO;
break;
}
@@ -2443,12 +2457,12 @@ static unsigned int n_tty_poll(struct tty_struct *tty, struct file *file,
poll_wait(file, &tty->read_wait, wait);
poll_wait(file, &tty->write_wait, wait);
+ if (check_other_done(tty))
+ mask |= POLLHUP;
if (input_available_p(tty, 1))
mask |= POLLIN | POLLRDNORM;
if (tty->packet && tty->link->ctrl_status)
mask |= POLLPRI | POLLIN | POLLRDNORM;
- if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
- mask |= POLLHUP;
if (tty_hung_up_p(file))
mask |= POLLHUP;
if (!(mask & (POLLHUP | POLLIN | POLLRDNORM))) {
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index e72ee629cead1b0af93c54b96395cbfc98b69975..4d5e8409769c3cc412ba5d428e0f179b4b44fdad 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -53,9 +53,8 @@ static void pty_close(struct tty_struct *tty, struct file *filp)
/* Review - krefs on tty_link ?? */
if (!tty->link)
return;
- tty_flush_to_ldisc(tty->link);
set_bit(TTY_OTHER_CLOSED, &tty->link->flags);
- wake_up_interruptible(&tty->link->read_wait);
+ tty_flip_buffer_push(tty->link->port);
wake_up_interruptible(&tty->link->write_wait);
if (tty->driver->subtype == PTY_TYPE_MASTER) {
set_bit(TTY_OTHER_CLOSED, &tty->flags);
@@ -243,7 +242,9 @@ static int pty_open(struct tty_struct *tty, struct file *filp)
goto out;
clear_bit(TTY_IO_ERROR, &tty->flags);
+ /* TTY_OTHER_CLOSED must be cleared before TTY_OTHER_DONE */
clear_bit(TTY_OTHER_CLOSED, &tty->link->flags);
+ clear_bit(TTY_OTHER_DONE, &tty->link->flags);
set_bit(TTY_THROTTLED, &tty->flags);
return 0;
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 5a4e9d579585f9c5165839db0fec8e368dfb8133..6f5a0720a8c8eead6c23f37c359c516730013cef 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -1639,6 +1639,9 @@ static int pl011_startup(struct uart_port *port)
writew(uap->vendor->ifls, uap->port.membase + UART011_IFLS);
+ /* Assume that TX IRQ doesn't work until we see one: */
+ uap->tx_irq_seen = 0;
+
spin_lock_irq(&uap->port.lock);
/* restore RTS and DTR */
@@ -1702,7 +1705,7 @@ static void pl011_shutdown(struct uart_port *port)
spin_lock_irq(&uap->port.lock);
uap->im = 0;
writew(uap->im, uap->port.membase + UART011_IMSC);
- writew(0xffff & ~UART011_TXIS, uap->port.membase + UART011_ICR);
+ writew(0xffff, uap->port.membase + UART011_ICR);
spin_unlock_irq(&uap->port.lock);
pl011_dma_shutdown(uap);
diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
index 5fdc9f3ecd644d9b58a0f9a10f150296b68282d7..6dc471e30e793aaf99bfc1bac6d376387d9e21a5 100644
--- a/drivers/tty/serial/earlycon.c
+++ b/drivers/tty/serial/earlycon.c
@@ -187,13 +187,8 @@ static int __init param_setup_earlycon(char *buf)
return 0;
err = setup_earlycon(buf);
- if (err == -ENOENT) {
- pr_warn("no match for %s\n", buf);
- err = 0;
- } else if (err == -EALREADY) {
- pr_warn("already registered\n");
- err = 0;
- }
+ if (err == -ENOENT || err == -EALREADY)
+ return 0;
return err;
}
early_param("earlycon", param_setup_earlycon);
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 211479aa34bb20d5375078afb103829faa5bfd84..7f49172ccd8673b316b3b82ab21282885ef983eb 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -1735,6 +1735,8 @@ static int serial_omap_probe(struct platform_device *pdev)
err_add_port:
pm_runtime_put(&pdev->dev);
pm_runtime_disable(&pdev->dev);
+ pm_qos_remove_request(&up->pm_qos_request);
+ device_init_wakeup(up->dev, false);
err_rs485:
err_port_line:
return ret;
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 75661641f5fe068237e7830acd9472383964da3a..2f78b77f0f8180fa07df27ab2ab931cf73f53587 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -37,6 +37,28 @@
#define TTY_BUFFER_PAGE (((PAGE_SIZE - sizeof(struct tty_buffer)) / 2) & ~0xFF)
+/*
+ * If all tty flip buffers have been processed by flush_to_ldisc() or
+ * dropped by tty_buffer_flush(), check if the linked pty has been closed.
+ * If so, wake the reader/poll to process
+ */
+static inline void check_other_closed(struct tty_struct *tty)
+{
+ unsigned long flags, old;
+
+ /* transition from TTY_OTHER_CLOSED => TTY_OTHER_DONE must be atomic */
+ for (flags = ACCESS_ONCE(tty->flags);
+ test_bit(TTY_OTHER_CLOSED, &flags);
+ ) {
+ old = flags;
+ __set_bit(TTY_OTHER_DONE, &flags);
+ flags = cmpxchg(&tty->flags, old, flags);
+ if (old == flags) {
+ wake_up_interruptible(&tty->read_wait);
+ break;
+ }
+ }
+}
/**
* tty_buffer_lock_exclusive - gain exclusive access to buffer
@@ -229,6 +251,8 @@ void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld)
if (ld && ld->ops->flush_buffer)
ld->ops->flush_buffer(tty);
+ check_other_closed(tty);
+
atomic_dec(&buf->priority);
mutex_unlock(&buf->lock);
}
@@ -471,8 +495,10 @@ static void flush_to_ldisc(struct work_struct *work)
smp_rmb();
count = head->commit - head->read;
if (!count) {
- if (next == NULL)
+ if (next == NULL) {
+ check_other_closed(tty);
break;
+ }
buf->head = next;
tty_buffer_free(port, head);
continue;
@@ -488,19 +514,6 @@ static void flush_to_ldisc(struct work_struct *work)
tty_ldisc_deref(disc);
}
-/**
- * tty_flush_to_ldisc
- * @tty: tty to push
- *
- * Push the terminal flip buffers to the line discipline.
- *
- * Must not be called from IRQ context.
- */
-void tty_flush_to_ldisc(struct tty_struct *tty)
-{
- flush_work(&tty->port->buf.work);
-}
-
/**
* tty_flip_buffer_push - terminal
* @port: tty port to push
diff --git a/include/linux/tty.h b/include/linux/tty.h
index fe5623c9af715fda985da02bcecb1c9451b3789c..d76631f615c224ac29e64198050279aa01e97880 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -339,6 +339,7 @@ struct tty_file_private {
#define TTY_EXCLUSIVE 3 /* Exclusive open mode */
#define TTY_DEBUG 4 /* Debugging */
#define TTY_DO_WRITE_WAKEUP 5 /* Call write_wakeup after queuing new */
+#define TTY_OTHER_DONE 6 /* Closed pty has completed input processing */
#define TTY_LDISC_OPEN 11 /* Line discipline is open */
#define TTY_PTY_LOCK 16 /* pty private */
#define TTY_NO_WRITE_SPLIT 17 /* Preserve write boundaries to driver */
@@ -462,7 +463,6 @@ extern int tty_hung_up_p(struct file *filp);
extern void do_SAK(struct tty_struct *tty);
extern void __do_SAK(struct tty_struct *tty);
extern void no_tty(void);
-extern void tty_flush_to_ldisc(struct tty_struct *tty);
extern void tty_buffer_free_all(struct tty_port *port);
extern void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld);
extern void tty_buffer_init(struct tty_port *port);