diff options
Diffstat (limited to 'drivers/char/cyclades.c')
| -rw-r--r-- | drivers/char/cyclades.c | 30 |
1 files changed, 2 insertions, 28 deletions
diff --git a/drivers/char/cyclades.c b/drivers/char/cyclades.c index c1c67281750da..87b2fb5108713 100644 --- a/drivers/char/cyclades.c +++ b/drivers/char/cyclades.c @@ -748,18 +748,6 @@ static struct cyclades_port cy_port[NR_PORTS]; static int cy_next_channel; /* next minor available */ /* - * tmp_buf is used as a temporary buffer by serial_write. We need to - * lock it in case the copy_from_user blocks while swapping in a page, - * and some other program tries to do a serial write at the same time. - * Since the lock will only come under contention when the system is - * swapping and available memory is low, it makes sense to share one - * buffer across all the serial ports, since it significantly saves - * memory if large numbers of serial ports are open. This buffer is - * allocated when the first cy_open occurs. - */ -static unsigned char *tmp_buf; - -/* * This is used to look up the divisor speeds and the timeouts * We're normally limited to 15 distinct baud rates. The extra * are accessed via settings in info->flags. @@ -2466,7 +2454,6 @@ cy_open(struct tty_struct *tty, struct file * filp) { struct cyclades_port *info; int retval, line; - unsigned long page; line = tty->index; if ((line < 0) || (NR_PORTS <= line)){ @@ -2545,15 +2532,6 @@ cy_open(struct tty_struct *tty, struct file * filp) printk("cyc:cy_open (%d): incrementing count to %d\n", current->pid, info->count); #endif - if (!tmp_buf) { - page = get_zeroed_page(GFP_KERNEL); - if (!page) - return -ENOMEM; - if (tmp_buf) - free_page(page); - else - tmp_buf = (unsigned char *) page; - } /* * If the port is the middle of closing, bail out now @@ -2832,7 +2810,7 @@ cy_write(struct tty_struct * tty, const unsigned char *buf, int count) return 0; } - if (!info->xmit_buf || !tmp_buf) + if (!info->xmit_buf) return 0; CY_LOCK(info, flags); @@ -5205,7 +5183,7 @@ done: extra ports are ignored. */ -static struct tty_operations cy_ops = { +static const struct tty_operations cy_ops = { .open = cy_open, .close = cy_close, .write = cy_write, @@ -5490,10 +5468,6 @@ cy_cleanup_module(void) #endif } } - if (tmp_buf) { - free_page((unsigned long) tmp_buf); - tmp_buf = NULL; - } } /* cy_cleanup_module */ module_init(cy_init); |