提交 f204d267 编写于 作者: J Jiri Slaby 提交者: Linus Torvalds

[PATCH] Char: moxa, remove unused allocated page

moxaXmitBuff is almost unused -- only one byte from the whole PAGE_SIZE bytes
is used.  Do not alloc so much space for almost anything.  Also remove lock
protecting this page allocation.
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
上级 34f5a398
......@@ -212,12 +212,10 @@ module_param(verbose, bool, 0644);
static struct tty_driver *moxaDriver;
static struct moxa_str moxaChannels[MAX_PORTS];
static unsigned char *moxaXmitBuff;
static int moxaTimer_on;
static struct timer_list moxaTimer;
static int moxaEmptyTimer_on[MAX_PORTS];
static struct timer_list moxaEmptyTimer[MAX_PORTS];
static struct semaphore moxaBuffSem;
/*
* static functions:
......@@ -343,7 +341,6 @@ static int __init moxa_init(void)
if (!moxaDriver)
return -ENOMEM;
init_MUTEX(&moxaBuffSem);
moxaDriver->owner = THIS_MODULE;
moxaDriver->name = "ttyMX";
moxaDriver->major = ttymajor;
......@@ -360,8 +357,6 @@ static int __init moxa_init(void)
moxaDriver->flags = TTY_DRIVER_REAL_RAW;
tty_set_operations(moxaDriver, &moxa_ops);
moxaXmitBuff = NULL;
for (i = 0, ch = moxaChannels; i < MAX_PORTS; i++, ch++) {
ch->type = PORT_16550A;
ch->port = i;
......@@ -533,7 +528,6 @@ static int moxa_open(struct tty_struct *tty, struct file *filp)
struct moxa_str *ch;
int port;
int retval;
unsigned long page;
port = PORTNO(tty);
if (port == MAX_PORTS) {
......@@ -543,21 +537,6 @@ static int moxa_open(struct tty_struct *tty, struct file *filp)
tty->driver_data = NULL;
return (-ENODEV);
}
down(&moxaBuffSem);
if (!moxaXmitBuff) {
page = get_zeroed_page(GFP_KERNEL);
if (!page) {
up(&moxaBuffSem);
return (-ENOMEM);
}
/* This test is guarded by the BuffSem so no longer needed
delete me in 2.5 */
if (moxaXmitBuff)
free_page(page);
else
moxaXmitBuff = (unsigned char *) page;
}
up(&moxaBuffSem);
ch = &moxaChannels[port];
ch->count++;
......@@ -739,8 +718,7 @@ static void moxa_put_char(struct tty_struct *tty, unsigned char c)
return;
port = ch->port;
spin_lock_irqsave(&moxa_lock, flags);
moxaXmitBuff[0] = c;
MoxaPortWriteData(port, moxaXmitBuff, 1);
MoxaPortWriteData(port, &c, 1);
spin_unlock_irqrestore(&moxa_lock, flags);
/************************************************
if ( !(ch->statusflags & LOWWAIT) && (MoxaPortTxFree(port) <= 100) )
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册