[ 005/167] [PATCH] ARM: clps711x: serial driver hungs are a result of call disable_irq within ISR

Ben Hutchings
2012-05-09T05:52:20Z

From: Alexander Shiyan <shc_work@mail.ru>

commit 7a6fbc9a887193a1e9f8658703881c528040afbc upstream.

Since 2.6.30-rc1 clps711x serial driver hungs system. This is a result
of call disable_irq from ISR. synchronize_irq waits for end of interrupt
and goes to infinite loop. This patch fix this problem.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/tty/serial/clps711x.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/tty/serial/clps711x.c b/drivers/tty/serial/clps711x.c
index e6c3dbd..836fe273 100644
--- a/drivers/tty/serial/clps711x.c
+++ b/drivers/tty/serial/clps711x.c
@@ -154,10 +154,9 @@ static irqreturn_t clps711xuart_int_tx(int irq, void *dev_id)
port->x_char = 0;
return IRQ_HANDLED;
}
- if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
- clps711xuart_stop_tx(port);
- return IRQ_HANDLED;
- }
+
+ if (uart_circ_empty(xmit) || uart_tx_stopped(port))
+ goto disable_tx_irq;

count = port->fifosize >> 1;
do {
@@ -171,8 +170,11 @@ static irqreturn_t clps711xuart_int_tx(int irq, void *dev_id)
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);

- if (uart_circ_empty(xmit))
- clps711xuart_stop_tx(port);
+ if (uart_circ_empty(xmit)) {
+ disable_tx_irq:
+ disable_irq_nosync(TX_IRQ(port));
+ tx_enabled(port) = 0;
+ }

return IRQ_HANDLED;
}
--
1.7.10