[PATCH 07/67] serial: replace open coded mutex with a real mutex in mrst_max3110.c
in [Kernel]
|
Prev: [PATCH 25/67] tty: serial - fix tty back references in termios
Next: [PULL REQUEST] ext3 & quota fixes and cleanups for 2.6.36
From: Greg Kroah-Hartman on 5 Aug 2010 18:50 From: Arjan van de Ven <arjan(a)linux.intel.com> 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(a)linux.intel.com> Signed-off-by: Alan Cox <alan(a)linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)suse.de> --- drivers/serial/mrst_max3110.c | 15 ++++++++------- 1 files changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/serial/mrst_max3110.c b/drivers/serial/mrst_max3110.c index f9c01ae..0341853 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; -- 1.7.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |