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

From: Jiri Slaby
Date: Wed Apr 25 2007 - 09:54:45 EST


Matthias Kaehlcke napsal(a):
> 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;

I think that ERESTARTSYS is appropriate here.

reagrds,
--
http://www.fi.muni.cz/~xslaby/ Jiri Slaby
faculty of informatics, masaryk university, brno, cz
e-mail: jirislaby gmail com, gpg pubkey fingerprint:
B674 9967 0407 CE62 ACC8 22A0 32CC 55C3 39D4 7A7E
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/