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use mutex instead of semaphore in RocketPort driver 

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

Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hifive-unleashed-5.1
Matthias Kaehlcke 2007-05-08 00:32:00 -07:00 committed by Linus Torvalds
parent 6bdb6b620e
commit 69f545ea6a
2 changed files with 14 additions and 9 deletions
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19
drivers/char/rocket.c
View File

@ -81,6 +81,7 @@
#include <linux/string.h> #include <linux/string.h>
#include <linux/fcntl.h> #include <linux/fcntl.h>
#include <linux/ptrace.h> #include <linux/ptrace.h>
#include <linux/mutex.h>
#include <linux/ioport.h> #include <linux/ioport.h>
#include <linux/delay.h> #include <linux/delay.h>
#include <linux/wait.h> #include <linux/wait.h>
@ -89,7 +90,6 @@
#include <asm/atomic.h> #include <asm/atomic.h>
#include <linux/bitops.h> #include <linux/bitops.h>
#include <linux/spinlock.h> #include <linux/spinlock.h>
#include <asm/semaphore.h>
#include <linux/init.h> #include <linux/init.h>
/****** RocketPort includes ******/ /****** RocketPort includes ******/
@ -698,7 +698,7 @@ static void init_r_port(int board, int aiop, int chan, struct pci_dev *pci_dev)
} }
} }
spin_lock_init(&info->slock); spin_lock_init(&info->slock);
sema_init(&info->write_sem, 1); mutex_init(&info->write_mtx);
rp_table[line] = info; rp_table[line] = info;
if (pci_dev) if (pci_dev)
tty_register_device(rocket_driver, line, &pci_dev->dev); tty_register_device(rocket_driver, line, &pci_dev->dev);
@ -1657,8 +1657,11 @@ static void rp_put_char(struct tty_struct *tty, unsigned char ch)
if (rocket_paranoia_check(info, "rp_put_char")) if (rocket_paranoia_check(info, "rp_put_char"))
return; return;
/* Grab the port write semaphore, locking out other processes that try to write to this port */ /*
down(&info->write_sem); * Grab the port write mutex, locking out other processes that try to
* write to this port
*/
mutex_lock(&info->write_mtx);
#ifdef ROCKET_DEBUG_WRITE #ifdef ROCKET_DEBUG_WRITE
printk(KERN_INFO "rp_put_char %c...", ch); printk(KERN_INFO "rp_put_char %c...", ch);
@ -1680,12 +1683,12 @@ static void rp_put_char(struct tty_struct *tty, unsigned char ch)
info->xmit_fifo_room--; info->xmit_fifo_room--;
} }
spin_unlock_irqrestore(&info->slock, flags); spin_unlock_irqrestore(&info->slock, flags);
up(&info->write_sem); mutex_unlock(&info->write_mtx);
} }
/* /*
* Exception handler - write routine, called when user app writes to the device. * Exception handler - write routine, called when user app writes to the device.
* A per port write semaphore is used to protect from another process writing to * A per port write mutex is used to protect from another process writing to
* this port at the same time. This other process could be running on the other CPU * this port at the same time. This other process could be running on the other CPU
* or get control of the CPU if the copy_from_user() blocks due to a page fault (swapped out). * or get control of the CPU if the copy_from_user() blocks due to a page fault (swapped out).
* Spinlocks protect the info xmit members. * Spinlocks protect the info xmit members.
@ -1702,7 +1705,7 @@ static int rp_write(struct tty_struct *tty,
if (count <= 0 || rocket_paranoia_check(info, "rp_write")) if (count <= 0 || rocket_paranoia_check(info, "rp_write"))
return 0; return 0;
down_interruptible(&info->write_sem); mutex_lock_interruptible(&info->write_mtx);
#ifdef ROCKET_DEBUG_WRITE #ifdef ROCKET_DEBUG_WRITE
printk(KERN_INFO "rp_write %d chars...", count); printk(KERN_INFO "rp_write %d chars...", count);
@ -1773,7 +1776,7 @@ end:
wake_up_interruptible(&tty->poll_wait); wake_up_interruptible(&tty->poll_wait);
#endif #endif
} }
up(&info->write_sem); mutex_unlock(&info->write_mtx);
return retval; return retval;
} }

4
drivers/char/rocket_int.h
View File

@ -15,6 +15,8 @@
#define ROCKET_TYPE_MODEMIII 3 #define ROCKET_TYPE_MODEMIII 3
#define ROCKET_TYPE_PC104 4 #define ROCKET_TYPE_PC104 4
#include <linux/mutex.h>
#include <asm/io.h> #include <asm/io.h>
#include <asm/byteorder.h> #include <asm/byteorder.h>
@ -1171,7 +1173,7 @@ struct r_port {
struct wait_queue *close_wait; struct wait_queue *close_wait;
#endif #endif
spinlock_t slock; spinlock_t slock;
struct semaphore write_sem; struct mutex write_mtx;
}; };
#define RPORT_MAGIC 0x525001 #define RPORT_MAGIC 0x525001