[PATCH] use mutex instead of semaphore in RocketPort driver v2

From: Matthias Kaehlcke
Date: Wed Apr 25 2007 - 09:06:02 EST


the RocketPort driver uses a semaphore as mutex. use the mutex API
instead of the (binary) semaphore

Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@xxxxxxxxx>

--

diff --git a/drivers/char/rocket.c b/drivers/char/rocket.c
index 76357c8..7d23790 100644
--- a/drivers/char/rocket.c
+++ b/drivers/char/rocket.c
@@ -702,7 +702,7 @@ static void init_r_port(int board, int aiop, int chan, struct pci_dev *pci_dev)
}
}
spin_lock_init(&info->slock);
- sema_init(&info->write_sem, 1);
+ mutex_init(&info->write_mtx);
rp_table[line] = info;
if (pci_dev)
tty_register_device(rocket_driver, line, &pci_dev->dev);
@@ -1662,7 +1662,7 @@ static void rp_put_char(struct tty_struct *tty, unsigned char ch)
return;

/* Grab the port write semaphore, locking out other processes that try to write to this port */
- down(&info->write_sem);
+ mutex_lock(&info->write_mtx);

#ifdef ROCKET_DEBUG_WRITE
printk(KERN_INFO "rp_put_char %c...", ch);
@@ -1684,7 +1684,7 @@ static void rp_put_char(struct tty_struct *tty, unsigned char ch)
info->xmit_fifo_room--;
}
spin_unlock_irqrestore(&info->slock, flags);
- up(&info->write_sem);
+ mutex_unlock(&info->write_mtx);
}

/*
@@ -1706,7 +1706,8 @@ static int rp_write(struct tty_struct *tty,
if (count <= 0 || rocket_paranoia_check(info, "rp_write"))
return 0;

- down_interruptible(&info->write_sem);
+ if(mutex_lock_interruptible(&info->write_mtx))
+ return -EINTR;

#ifdef ROCKET_DEBUG_WRITE
printk(KERN_INFO "rp_write %d chars...", count);
@@ -1777,7 +1778,7 @@ end:
wake_up_interruptible(&tty->poll_wait);
#endif
}
- up(&info->write_sem);
+ mutex_unlock(&info->write_mtx);
return retval;
}

diff --git a/drivers/char/rocket_int.h b/drivers/char/rocket_int.h
index 3a8bcc8..04bcf61 100644
--- a/drivers/char/rocket_int.h
+++ b/drivers/char/rocket_int.h
@@ -1171,7 +1171,7 @@ struct r_port {
struct wait_queue *close_wait;
#endif
spinlock_t slock;
- struct semaphore write_sem;
+ struct mutex write_mtx;
};

#define RPORT_MAGIC 0x525001

--
Matthias Kaehlcke
Linux Application Developer
Barcelona


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their condition. But when they get angry, they bring about a change
(Malcolm X)
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