Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-27 22:51:35 +00:00
Code Issues Packages Projects Releases Wiki Activity

serial: mrst_max3110: Fix race condition between spi transfers

Browse Source 
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@intel.com>
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Bin Gao 2013-10-09 10:39:17 +08:00 committed by Greg Kroah-Hartman
parent 09238443c6
commit b6951b8a63
1 changed files with 4 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/tty/serial/mrst_max3110.c
View File

@ -61,6 +61,7 @@ struct uart_max3110 {
struct task_struct *main_thread; struct task_struct *main_thread;
struct task_struct *read_thread; struct task_struct *read_thread;
struct mutex thread_mutex; struct mutex thread_mutex;
struct mutex io_mutex;
u32 baud; u32 baud;
u16 cur_conf; u16 cur_conf;
@ -90,6 +91,7 @@ static int max3110_write_then_read(struct uart_max3110 *max,
struct spi_transfer x; struct spi_transfer x;
int ret; int ret;
mutex_lock(&max->io_mutex);
spi_message_init(&message); spi_message_init(&message);
memset(&x, 0, sizeof x); memset(&x, 0, sizeof x);
x.len = len; x.len = len;
@ -104,6 +106,7 @@ static int max3110_write_then_read(struct uart_max3110 *max,
/* Do the i/o */ /* Do the i/o */
ret = spi_sync(spi, &message); ret = spi_sync(spi, &message);
mutex_unlock(&max->io_mutex);
return ret; return ret;
} }
@ -805,6 +808,7 @@ static int serial_m3110_probe(struct spi_device *spi)
max->irq = (u16)spi->irq; max->irq = (u16)spi->irq;
mutex_init(&max->thread_mutex); mutex_init(&max->thread_mutex);
mutex_init(&max->io_mutex);
max->word_7bits = 0; max->word_7bits = 0;
max->parity = 0; max->parity = 0;