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Diffstat (limited to 'drivers/char/rocket.c')
-rw-r--r--drivers/char/rocket.c19
1 files changed, 11 insertions, 8 deletions
diff --git a/drivers/char/rocket.c b/drivers/char/rocket.c
index e249d8cfcd06..61a63da420c2 100644
--- a/drivers/char/rocket.c
+++ b/drivers/char/rocket.c
@@ -81,6 +81,7 @@
81#include <linux/string.h> 81#include <linux/string.h>
82#include <linux/fcntl.h> 82#include <linux/fcntl.h>
83#include <linux/ptrace.h> 83#include <linux/ptrace.h>
84#include <linux/mutex.h>
84#include <linux/ioport.h> 85#include <linux/ioport.h>
85#include <linux/delay.h> 86#include <linux/delay.h>
86#include <linux/wait.h> 87#include <linux/wait.h>
@@ -89,7 +90,6 @@
89#include <asm/atomic.h> 90#include <asm/atomic.h>
90#include <linux/bitops.h> 91#include <linux/bitops.h>
91#include <linux/spinlock.h> 92#include <linux/spinlock.h>
92#include <asm/semaphore.h>
93#include <linux/init.h> 93#include <linux/init.h>
94 94
95/****** RocketPort includes ******/ 95/****** RocketPort includes ******/
@@ -698,7 +698,7 @@ static void init_r_port(int board, int aiop, int chan, struct pci_dev *pci_dev)
698 } 698 }
699 } 699 }
700 spin_lock_init(&info->slock); 700 spin_lock_init(&info->slock);
701 sema_init(&info->write_sem, 1); 701 mutex_init(&info->write_mtx);
702 rp_table[line] = info; 702 rp_table[line] = info;
703 if (pci_dev) 703 if (pci_dev)
704 tty_register_device(rocket_driver, line, &pci_dev->dev); 704 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)
1657 if (rocket_paranoia_check(info, "rp_put_char")) 1657 if (rocket_paranoia_check(info, "rp_put_char"))
1658 return; 1658 return;
1659 1659
1660 /* Grab the port write semaphore, locking out other processes that try to write to this port */ 1660 /*
1661 down(&info->write_sem); 1661 * Grab the port write mutex, locking out other processes that try to
1662 * write to this port
1663 */
1664 mutex_lock(&info->write_mtx);
1662 1665
1663#ifdef ROCKET_DEBUG_WRITE 1666#ifdef ROCKET_DEBUG_WRITE
1664 printk(KERN_INFO "rp_put_char %c...", ch); 1667 printk(KERN_INFO "rp_put_char %c...", ch);
@@ -1680,12 +1683,12 @@ static void rp_put_char(struct tty_struct *tty, unsigned char ch)
1680 info->xmit_fifo_room--; 1683 info->xmit_fifo_room--;
1681 } 1684 }
1682 spin_unlock_irqrestore(&info->slock, flags); 1685 spin_unlock_irqrestore(&info->slock, flags);
1683 up(&info->write_sem); 1686 mutex_unlock(&info->write_mtx);
1684} 1687}
1685 1688
1686/* 1689/*
1687 * Exception handler - write routine, called when user app writes to the device. 1690 * Exception handler - write routine, called when user app writes to the device.
1688 * A per port write semaphore is used to protect from another process writing to 1691 * A per port write mutex is used to protect from another process writing to
1689 * this port at the same time. This other process could be running on the other CPU 1692 * this port at the same time. This other process could be running on the other CPU
1690 * or get control of the CPU if the copy_from_user() blocks due to a page fault (swapped out). 1693 * or get control of the CPU if the copy_from_user() blocks due to a page fault (swapped out).
1691 * Spinlocks protect the info xmit members. 1694 * Spinlocks protect the info xmit members.
@@ -1702,7 +1705,7 @@ static int rp_write(struct tty_struct *tty,
1702 if (count <= 0 || rocket_paranoia_check(info, "rp_write")) 1705 if (count <= 0 || rocket_paranoia_check(info, "rp_write"))
1703 return 0; 1706 return 0;
1704 1707
1705 down_interruptible(&info->write_sem); 1708 mutex_lock_interruptible(&info->write_mtx);
1706 1709
1707#ifdef ROCKET_DEBUG_WRITE 1710#ifdef ROCKET_DEBUG_WRITE
1708 printk(KERN_INFO "rp_write %d chars...", count); 1711 printk(KERN_INFO "rp_write %d chars...", count);
@@ -1773,7 +1776,7 @@ end:
1773 wake_up_interruptible(&tty->poll_wait); 1776 wake_up_interruptible(&tty->poll_wait);
1774#endif 1777#endif
1775 } 1778 }
1776 up(&info->write_sem); 1779 mutex_unlock(&info->write_mtx);
1777 return retval; 1780 return retval;
1778} 1781}
1779 1782