[GIT PATCH] TTY fixes for 2.6.34-git

[GIT PATCH] TTY fixes for 2.6.34-git

[Greg KH]

Here are 3 bugfixes for your 2.6.34-git tree.

One is a regression from .33, and the other 2 fix reported problems and
are being sent to the -stable trees as well.

Please pull from:
	master.kernel.org:/pub/scm/linux/kernel/git/gregkh/tty-2.6.git/

These patches have been in the linux-next tree for a while now.

Patches will be sent to the linux-kernel mailing list, if anyone wants
to see them.

thanks,

greg k-h

------------

 drivers/char/tty_io.c         |    1 +
 drivers/serial/imx.c          |   10 +++++++++-
 drivers/serial/mpc52xx_uart.c |    2 +-
 3 files changed, 11 insertions(+), 2 deletions(-)

---------------

Alan Cox (1):
      tty: Fix unbalanced BKL handling in error path

Anatolij Gustschin (1):
      serial: mpc52xx_uart: fix null pointer dereference

Valentin Longchamp (1):
      serial: imx.c: fix CTS trigger level lower to avoid lost chars

[PATCH 1/3] serial: mpc52xx_uart: fix null pointer dereference

[Greg Kroah-Hartman]

From: Anatolij Gustschin <agust@denx.de>

Commit 6acc6833510db8f72b5ef343296d97480555fda9
introduced NULL pointer dereference and kernel crash
on ppc32 machines while booting. Fix this bug now.

Reported-by: Leonardo Chiquitto <leonardo.lists@gmail.com>
Tested-by: Leonardo Chiquitto <leonardo.lists@gmail.com>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/serial/mpc52xx_uart.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/serial/mpc52xx_uart.c b/drivers/serial/mpc52xx_uart.c
index a176ab4..02469c3 100644
--- a/drivers/serial/mpc52xx_uart.c
+++ b/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;
-- 
1.7.1

[PATCH 2/3] tty: Fix unbalanced BKL handling in error path

[Greg Kroah-Hartman]

From: Alan Cox <alan@linux.intel.com>

Arnd noted:

After the "retry_open:" label, we first get the tty_mutex
and then the BKL. However a the end of tty_open, we jump
back to retry_open with the BKL still held. If we run into
this case, the tty_open function will be left with the BKL
still held.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/char/tty_io.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 6da962c..d71f0fc 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -1875,6 +1875,7 @@ got_driver:
 		 */
 		if (filp->f_op == &hung_up_tty_fops)
 			filp->f_op = &tty_fops;
+		unlock_kernel();
 		goto retry_open;
 	}
 	unlock_kernel();
-- 
1.7.1

[PATCH 3/3] serial: imx.c: fix CTS trigger level lower to avoid lost chars

[Greg Kroah-Hartman]

From: Valentin Longchamp <valentin.longchamp@epfl.ch>

The imx CTS trigger level is left at its reset value that is 32
chars. Since the RX FIFO has 32 entries, when CTS is raised, the
FIFO already is full. However, some serial port devices first empty
their TX FIFO before stopping when CTS is raised, resulting in lost
chars.

This patch sets the trigger level lower so that other chars arrive
after CTS is raised, there is still room for 16 of them.

Signed-off-by: Valentin Longchamp<valentin.longchamp@epfl.ch>
Tested-by: Philippe Rétornaz<philippe.retornaz@epfl.ch>
Acked-by: Wolfram Sang<w.sang@pengutronix.de>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/serial/imx.c |   10 +++++++++-
 1 files changed, 9 insertions(+), 1 deletions(-)

diff --git a/drivers/serial/imx.c b/drivers/serial/imx.c
index 4315b23..eacb588 100644
--- a/drivers/serial/imx.c
+++ b/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)) {
-- 
1.7.1