[PATCH 1/2] Staging: ipack/devices/ipoctal: fix dereference NULL pointer

[PATCH 1/2] Staging: ipack/devices/ipoctal: fix dereference NULL pointer

[Samuel Iglesias Gonsálvez]

After opening and closing the file /dev/ipoctal.X.Y.Z for the second time, it
gives a kernel oops due to a dereference of a NULL pointer.

The problem was that tty->driver_data was not properly initialized when
accessing the file for the second time.

Reported-by: Alberto Garcia Gonzalez <agarcia@igalia.com>
Signed-off-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
---
 drivers/staging/ipack/devices/ipoctal.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/ipack/devices/ipoctal.c b/drivers/staging/ipack/devices/ipoctal.c
index a5af423..a1aae40 100644
--- a/drivers/staging/ipack/devices/ipoctal.c
+++ b/drivers/staging/ipack/devices/ipoctal.c
@@ -114,8 +114,6 @@ static int ipoctal_port_activate(struct tty_port *port, struct tty_struct *tty)
 
 	ipoctal_write_io_reg(ipoctal, &ipoctal->chan_regs[channel].u.w.cr,
 			     CR_ENABLE_RX);
-	tty->driver_data = ipoctal;
-
 	return 0;
 }
 
@@ -136,6 +134,8 @@ static int ipoctal_open(struct tty_struct *tty, struct file *file)
 	if (atomic_read(&ipoctal->open[channel]))
 		return -EBUSY;
 
+	tty->driver_data = ipoctal;
+
 	res = tty_port_open(&ipoctal->tty_port[channel], tty, file);
 	if (res)
 		return res;
-- 
1.7.10.4

[PATCH 2/2] Staging: ipack/devices/ipoctal: initialize the device in probe function

[Samuel Iglesias Gonsálvez]

Initialize the device when registering it. Sometimes the user access to it
and the device is in an unknown state, so it could fail.

Signed-off-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
---
 drivers/staging/ipack/devices/ipoctal.c |   14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/staging/ipack/devices/ipoctal.c b/drivers/staging/ipack/devices/ipoctal.c
index a1aae40..fd0e301 100644
--- a/drivers/staging/ipack/devices/ipoctal.c
+++ b/drivers/staging/ipack/devices/ipoctal.c
@@ -411,6 +411,20 @@ static int ipoctal_inst_slot(struct ipoctal *ipoctal, unsigned int bus_nr,
 	for (i = 0; i < NR_CHANNELS ; i++) {
 		ipoctal_write_io_reg(ipoctal, &ipoctal->chan_regs[i].u.w.cr,
 				     CR_DISABLE_RX | CR_DISABLE_TX);
+		ipoctal_write_cr_cmd(ipoctal, &ipoctal->chan_regs[i].u.w.cr,
+				     CR_CMD_RESET_RX);
+		ipoctal_write_cr_cmd(ipoctal, &ipoctal->chan_regs[i].u.w.cr,
+				     CR_CMD_RESET_TX);
+		ipoctal_write_io_reg(ipoctal,
+				     &ipoctal->chan_regs[i].u.w.mr,
+				     MR1_CHRL_8_BITS | MR1_ERROR_CHAR |
+				     MR1_RxINT_RxRDY); /* mr1 */
+		ipoctal_write_io_reg(ipoctal,
+				     &ipoctal->chan_regs[i].u.w.mr,
+				     0); /* mr2 */
+		ipoctal_write_io_reg(ipoctal,
+				     &ipoctal->chan_regs[i].u.w.csr,
+				     TX_CLK_9600  | RX_CLK_9600);
 	}
 
 	for (i = 0; i < IP_OCTAL_NB_BLOCKS; i++) {
-- 
1.7.10.4