use mutex instead of semaphore in RocketPort driver v2

PATCH In review Matthias Kaehlcke 2 participants 4 messages Apr 25, 2007 Char and misc drivers

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Matthias Kaehlcke

author

2007-04-25 13:05 UTC #0 lore raw

PATCH 1/1 use mutex instead of semaphore in RocketPort driver v2

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

Signed-off-by Matthias Kaehlcke <[email protected]>

drivers/char/rocket.c +6 -5

index 76357c8..7d23790 100644
@@ -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;
 }

drivers/char/rocket_int.h +1 -1

index 3a8bcc8..04bcf61 100644
@@ -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

Signature · 12 lines

Matthias Kaehlcke
Linux Application Developer
Barcelona


   Usually when people are sad, they don't do anything. They just cry over
     their condition. But when they get angry, they bring about a change
                              (Malcolm X)
                                                                 .''`.
    using free software / Debian GNU/Linux | http://debian.org  : :'  :
                                                                `. `'`
gpg --keyserver pgp.mit.edu --recv-keys 47D8E5D4                  `-

Jiri Slaby

2007-04-25 13:54 UTC #1 lore raw

Matthias Kaehlcke napsal(a):

Quoted 39 lines

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

Signed-off-by Matthias Kaehlcke <[email protected]>

drivers/char/rocket.c +3 -3

index 76357c8..7d23790 100644
@@ -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);
 }
 
 /*

drivers/char/rocket.c static int rp_write(struct tty_struct *tty, · line 1710

Quoted 6 lines

drivers/char/rocket.c +2 -1

@@ -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,

Signature · 4 lines

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

Matthias Kaehlcke

author

2007-04-25 14:04 UTC #2 lore raw

El Wed, Apr 25, 2007 at 03:54:36PM +0200 Jiri Slaby ha dit:

Quoted 8 lines

Matthias Kaehlcke napsal(a):
Quoted 5 lines
the RocketPort driver uses a semaphore as mutex. use the mutex API instead of the (binary) semaphore
Signed-off-by Matthias Kaehlcke <[email protected]>
I think that ERESTARTSYS is appropriate here.

thanks for your remark, i'll take it into account

Signature · 10 lines

Matthias Kaehlcke
Linux Application Developer
Barcelona

            Nothing is more despicable than respect based on fear
                              (Albert Camus)
                                                                 .''`.
    using free software / Debian GNU/Linux | http://debian.org  : :'  :
                                                                `. `'`
gpg --keyserver pgp.mit.edu --recv-keys 47D8E5D4                  `-

Jiri Slaby

2007-04-25 13:58 UTC #3 lore raw

In reply to Matthias Kaehlcke

Matthias Kaehlcke napsal(a):

Quoted 39 lines

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

Signed-off-by Matthias Kaehlcke <[email protected]>

drivers/char/rocket.c +3 -3

index 76357c8..7d23790 100644
@@ -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);
 }
 
 /*

drivers/char/rocket.c static int rp_write(struct tty_struct *tty, · line 1709

Quoted 5 lines

drivers/char/rocket.c +1 -1

@@ -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))

and put a space here "if (".

regards,

Signature · 4 lines

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