From: Bin Gao <bin.gao@xxxxxxxxx>
There is a race between termios configuration and xmit that can cause the
intel_mid_ssp_spi driver to stall.
Serializing spi transactions fixes the problem.
Signed-off-by: Bin Gao <bin.gao@xxxxxxxxx>
Signed-off-by: Feng Tang <feng.tang@xxxxxxxxx>
---
drivers/tty/serial/mrst_max3110.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/drivers/tty/serial/mrst_max3110.c b/drivers/tty/serial/mrst_max3110.c
index ee77e73..565779d 100644
--- a/drivers/tty/serial/mrst_max3110.c
+++ b/drivers/tty/serial/mrst_max3110.c
@@ -61,6 +61,7 @@ struct uart_max3110 {
struct task_struct *main_thread;
struct task_struct *read_thread;
struct mutex thread_mutex;
+ struct mutex io_mutex;
u32 baud;
u16 cur_conf;
@@ -90,6 +91,7 @@ static int max3110_write_then_read(struct uart_max3110 *max,
struct spi_transfer x;
int ret;
+ mutex_lock(&max->io_mutex);
spi_message_init(&message);
memset(&x, 0, sizeof x);
x.len = len;
@@ -104,6 +106,7 @@ static int max3110_write_then_read(struct uart_max3110 *max,
/* Do the i/o */
ret = spi_sync(spi, &message);
+ mutex_unlock(&max->io_mutex);
return ret;
}
@@ -805,6 +808,7 @@ static int serial_m3110_probe(struct spi_device *spi)
max->irq = (u16)spi->irq;
mutex_init(&max->thread_mutex);
+ mutex_init(&max->io_mutex);
max->word_7bits = 0;
max->parity = 0;
--
1.7.0.4
--
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