Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6:
  serial: imx.c: fix CTS trigger level lower to avoid lost chars
  tty: Fix unbalanced BKL handling in error path
  serial: mpc52xx_uart: fix null pointer dereference

drivers/char/tty_io.c

@@ -1875,6 +1875,7 @@ static int tty_open(struct inode *inode, struct file *filp)
 		 */
 		if (filp->f_op == &hung_up_tty_fops)
 			filp->f_op = &tty_fops;
+		unlock_kernel();
 		goto retry_open;
 	}
 	unlock_kernel();

drivers/serial/imx.c

@@ -120,7 +120,8 @@
 #define  MX2_UCR3_RXDMUXSEL	 (1<<2)  /* RXD Muxed Input Select, on mx2/mx3 */
 #define  UCR3_INVT  	 (1<<1)  /* Inverted Infrared transmission */
 #define  UCR3_BPEN  	 (1<<0)  /* Preset registers enable */
-#define  UCR4_CTSTL_32   (32<<10) /* CTS trigger level (32 chars) */
+#define  UCR4_CTSTL_SHF  10      /* CTS trigger level shift */
+#define  UCR4_CTSTL_MASK 0x3F    /* CTS trigger is 6 bits wide */
 #define  UCR4_INVR  	 (1<<9)  /* Inverted infrared reception */
 #define  UCR4_ENIRI 	 (1<<8)  /* Serial infrared interrupt enable */
 #define  UCR4_WKEN  	 (1<<7)  /* Wake interrupt enable */
@@ -591,6 +592,9 @@ static int imx_setup_ufcr(struct imx_port *sport, unsigned int mode)
 	return 0;
 }
 
+/* half the RX buffer size */
+#define CTSTL 16
+
 static int imx_startup(struct uart_port *port)
 {
 	struct imx_port *sport = (struct imx_port *)port;
@@ -607,6 +611,10 @@ static int imx_startup(struct uart_port *port)
 	if (USE_IRDA(sport))
 		temp |= UCR4_IRSC;
 
+	/* set the trigger level for CTS */
+	temp &= ~(UCR4_CTSTL_MASK<<  UCR4_CTSTL_SHF);
+	temp |= CTSTL<<  UCR4_CTSTL_SHF;
+
 	writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
 
 	if (USE_IRDA(sport)) {

drivers/serial/mpc52xx_uart.c

@@ -1467,7 +1467,7 @@ mpc52xx_uart_init(void)
 	/*
 	 * Map the PSC FIFO Controller and init if on MPC512x.
 	 */
-	if (psc_ops->fifoc_init) {
+	if (psc_ops && psc_ops->fifoc_init) {
 		ret = psc_ops->fifoc_init();
 		if (ret)
 			return ret;