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authorArjan van de Ven <arjan@linux.intel.com>2010-06-17 11:02:06 +0100
committerGreg Kroah-Hartman <gregkh@suse.de>2010-08-10 13:47:39 -0700
commit68c16b4117cc746a91897d629b61e5f2af18c225 (patch)
treef681c2966cf731a32edc0f33e072a6f4b3272e5e /drivers/serial/mrst_max3110.c
parent99dd3f6b7e2ef5179f67503a401a99141708687a (diff)
serial: replace open coded mutex with a real mutex in mrst_max3110.c
The mrst_max3110.c driver uses an open coded, non atomic variable to create exclusion between two of its worker threads. More than that, while the main thread does a proper set-work-clear sequence, the other thread only does a test, with the result that no actual exclusion is happening. this patch replaces this open coded variable with a proper mutex in addition, the 'lock' spinlock is removed from the per adapter structure, the lock was only ever initialized but never used Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/serial/mrst_max3110.c')
-rw-r--r--drivers/serial/mrst_max3110.c15
1 files changed, 8 insertions, 7 deletions
diff --git a/drivers/serial/mrst_max3110.c b/drivers/serial/mrst_max3110.c
index f9c01aeb6f8..0341853e0c2 100644
--- a/drivers/serial/mrst_max3110.c
+++ b/drivers/serial/mrst_max3110.c
@@ -56,8 +56,7 @@ struct uart_max3110 {
wait_queue_head_t wq;
struct task_struct *main_thread;
struct task_struct *read_thread;
- int mthread_up;
- spinlock_t lock;
+ struct mutex thread_mutex;;
u32 baud;
u16 cur_conf;
@@ -397,7 +396,8 @@ static int max3110_main_thread(void *_max)
atomic_read(&max->con_tx_need) ||
atomic_read(&max->uart_tx_need)) ||
kthread_should_stop());
- max->mthread_up = 1;
+
+ mutex_lock(&max->thread_mutex);
#ifdef CONFIG_MRST_MAX3110_IRQ
if (atomic_read(&max->irq_pending)) {
@@ -417,7 +417,7 @@ static int max3110_main_thread(void *_max)
transmit_char(max);
atomic_set(&max->uart_tx_need, 0);
}
- max->mthread_up = 0;
+ mutex_unlock(&max->thread_mutex);
} while (!kthread_should_stop());
return ret;
@@ -444,8 +444,9 @@ static int max3110_read_thread(void *_max)
pr_info(PR_FMT "start read thread\n");
do {
- if (!max->mthread_up)
- max3110_console_receive(max);
+ mutex_lock(&max->thread_mutex);
+ max3110_console_receive(max);
+ mutex_unlock(&max->thread_mutex);
set_current_state(TASK_INTERRUPTIBLE);
schedule_timeout(HZ / 20);
@@ -745,7 +746,7 @@ static int serial_m3110_probe(struct spi_device *spi)
max->name = spi->modalias; /* use spi name as the name */
max->irq = (u16)spi->irq;
- spin_lock_init(&max->lock);
+ mutex_init(&max->thread_mutex);
max->word_7bits = 0;
max->parity = 0;