[PATCHv2 0/2] tty: serial: men_z135_uart.c: Updates for men_z135_uart

[PATCHv2 0/2] tty: serial: men_z135_uart.c: Updates for men_z135_uart

[Johannes Thumshirn]

Version two of the updates for the men_z135_uart, incorporating Peter's review
comments.

1/2: Use spin_lock_irq() in settermios() and spin_lock() in ISR to avoid
     deadlocks.
2/2: Removes the double initialization of the port.lock spinlock.

Johannes Thumshirn (2):
  tty: serial: men_z135_uart.c: Fix race between IRQ and set_termios()
  tty: serial: men_z135_uart.c: Don't initialize port->lock

 drivers/tty/serial/men_z135_uart.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

-- 
2.4.6

[PATCH 2/2] tty: serial: men_z135_uart.c: Don't initialize port->lock

[Johannes Thumshirn]

port->lock get's initialized in uart_add_one_port(), no need to do it
in men_z135_probe().

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Peter Hurley <peter@hurleysoftware.com>
---
 drivers/tty/serial/men_z135_uart.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/tty/serial/men_z135_uart.c b/drivers/tty/serial/men_z135_uart.c
index 5a41b8fb..b90e7b3 100644
--- a/drivers/tty/serial/men_z135_uart.c
+++ b/drivers/tty/serial/men_z135_uart.c
@@ -839,7 +839,6 @@ static int men_z135_probe(struct mcb_device *mdev,
 	uart->port.membase = NULL;
 	uart->mdev = mdev;
 
-	spin_lock_init(&uart->port.lock);
 	spin_lock_init(&uart->lock);
 
 	err = uart_add_one_port(&men_z135_driver, &uart->port);
-- 
2.4.6

Re: [PATCH 2/2] tty: serial: men_z135_uart.c: Don't initialize port->lock

[Peter Hurley]

On 08/06/2015 03:16 AM, Johannes Thumshirn wrote:
> port->lock get's initialized in uart_add_one_port(), no need to do it
> in men_z135_probe().

Reviewed-by: Peter Hurley <peter@hurleysoftware.com>

Re: [PATCHv2 1/2] tty: serial: men_z135_uart.c: Fix race between IRQ and set_termios()

[Peter Hurley]

On 08/06/2015 03:16 AM, Johannes Thumshirn wrote:
> Fix panic caused by a race between men_z135_intr() and men_z135_set_termios().
> 
> men_z135_intr() and men_z135_set_termios() both hold the struct uart_port::lock
> spinlock, but men_z135_intr() does a spin_lock_irqsave() and
> men_z135_set_termios() does a normal spin_lock(), which can lead to a deadlock
> when an interrupt is called while the lock is being helt by
> men_z135_set_termios().
> 
> This was discovered using a insmod, hardware looppback send/receive, rmmod
> stress test.

Reviewed-by: Peter Hurley <peter@hurleysoftware.com>