Merge tag 'tty-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial fixes from Greg KH:
 "Here are some small tty and serial driver fixes to resolve some
  reported problems:

   - led tty trigger fixes based on review and were acked by the led
     maintainer

   - revert a max310x serial driver patch as it was causing problems

   - revert a pty change as it was also causing problems

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'tty-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  Revert "drivers:tty:pty: Fix a race causing data loss on close"
  Revert "serial: max310x: rework RX interrupt handling"
  leds: trigger/tty: Use led_set_brightness_sync() from workqueue
  leds: trigger: Fix error path to not unlock the unlocked mutex

Author: torvalds

drivers/leds/trigger/ledtrig-tty.c

@@ -51,10 +51,8 @@ static ssize_t ttyname_store(struct device *dev,
 
 	if (size) {
 		ttyname = kmemdup_nul(buf, size, GFP_KERNEL);
-		if (!ttyname) {
-			ret = -ENOMEM;
-			goto out_unlock;
-		}
+		if (!ttyname)
+			return -ENOMEM;
 	} else {
 		ttyname = NULL;
 	}
@@ -69,7 +67,6 @@ static ssize_t ttyname_store(struct device *dev,
 
 	trigger_data->ttyname = ttyname;
 
-out_unlock:
 	mutex_unlock(&trigger_data->mutex);
 
 	if (ttyname && !running)
@@ -125,12 +122,12 @@ static void ledtrig_tty_work(struct work_struct *work)
 
 	if (icount.rx != trigger_data->rx ||
 	    icount.tx != trigger_data->tx) {
-		led_set_brightness(trigger_data->led_cdev, LED_ON);
+		led_set_brightness_sync(trigger_data->led_cdev, LED_ON);
 
 		trigger_data->rx = icount.rx;
 		trigger_data->tx = icount.tx;
 	} else {
-		led_set_brightness(trigger_data->led_cdev, LED_OFF);
+		led_set_brightness_sync(trigger_data->led_cdev, LED_OFF);
 	}
 
 out:

drivers/tty/pty.c

@@ -66,8 +66,7 @@ static void pty_close(struct tty_struct *tty, struct file *filp)
 	wake_up_interruptible(&tty->link->read_wait);
 	wake_up_interruptible(&tty->link->write_wait);
 	if (tty->driver->subtype == PTY_TYPE_MASTER) {
-		struct file *f;
-
+		set_bit(TTY_OTHER_CLOSED, &tty->flags);
 #ifdef CONFIG_UNIX98_PTYS
 		if (tty->driver == ptm_driver) {
 			mutex_lock(&devpts_mutex);
@@ -76,17 +75,7 @@ static void pty_close(struct tty_struct *tty, struct file *filp)
 			mutex_unlock(&devpts_mutex);
 		}
 #endif
-
-		/*
-		 * This hack is required because a program can open a
-		 * pty and redirect a console to it, but if the pty is
-		 * closed and the console is not released, then the
-		 * slave side will never close.  So release the
-		 * redirect when the master closes.
-		 */
-		f = tty_release_redirect(tty->link);
-		if (f)
-			fput(f);
+		tty_vhangup(tty->link);
 	}
 }
 

drivers/tty/serial/max310x.c

@@ -1056,9 +1056,9 @@ static int max310x_startup(struct uart_port *port)
 	max310x_port_update(port, MAX310X_MODE1_REG,
 			    MAX310X_MODE1_TRNSCVCTRL_BIT, 0);
 
-	/* Reset FIFOs */
-	max310x_port_write(port, MAX310X_MODE2_REG,
-			   MAX310X_MODE2_FIFORST_BIT);
+	/* Configure MODE2 register & Reset FIFOs*/
+	val = MAX310X_MODE2_RXEMPTINV_BIT | MAX310X_MODE2_FIFORST_BIT;
+	max310x_port_write(port, MAX310X_MODE2_REG, val);
 	max310x_port_update(port, MAX310X_MODE2_REG,
 			    MAX310X_MODE2_FIFORST_BIT, 0);
 
@@ -1086,27 +1086,8 @@ static int max310x_startup(struct uart_port *port)
 	/* Clear IRQ status register */
 	max310x_port_read(port, MAX310X_IRQSTS_REG);
 
-	/*
-	 * Let's ask for an interrupt after a timeout equivalent to
-	 * the receiving time of 4 characters after the last character
-	 * has been received.
-	 */
-	max310x_port_write(port, MAX310X_RXTO_REG, 4);
-
-	/*
-	 * Make sure we also get RX interrupts when the RX FIFO is
-	 * filling up quickly, so get an interrupt when half of the RX
-	 * FIFO has been filled in.
-	 */
-	max310x_port_write(port, MAX310X_FIFOTRIGLVL_REG,
-			   MAX310X_FIFOTRIGLVL_RX(MAX310X_FIFO_SIZE / 2));
-
-	/* Enable RX timeout interrupt in LSR */
-	max310x_port_write(port, MAX310X_LSR_IRQEN_REG,
-			   MAX310X_LSR_RXTO_BIT);
-
-	/* Enable LSR, RX FIFO trigger, CTS change interrupts */
-	val = MAX310X_IRQ_LSR_BIT  | MAX310X_IRQ_RXFIFO_BIT | MAX310X_IRQ_TXEMPTY_BIT;
+	/* Enable RX, TX, CTS change interrupts */
+	val = MAX310X_IRQ_RXEMPTY_BIT | MAX310X_IRQ_TXEMPTY_BIT;
 	max310x_port_write(port, MAX310X_IRQEN_REG, val | MAX310X_IRQ_CTS_BIT);
 
 	return 0;

drivers/tty/tty_io.c

@@ -544,9 +544,7 @@ EXPORT_SYMBOL_GPL(tty_wakeup);
  *	@tty: tty device
  *
  *	This is available to the pty code so if the master closes, if the
- *	slave is a redirect it can release the redirect.  It returns the
- *	filp for the redirect, which must be fput when the operations on
- *	the tty are completed.
+ *	slave is a redirect it can release the redirect.
  */
 struct file *tty_release_redirect(struct tty_struct *tty)
 {
@@ -561,6 +559,7 @@ struct file *tty_release_redirect(struct tty_struct *tty)
 
 	return f;
 }
+EXPORT_SYMBOL_GPL(tty_release_redirect);
 
 /**
  *	__tty_hangup		-	actual handler for hangup events