[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: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 23 deletions

diff --git a/drivers/char/moxa.c b/drivers/char/moxa.c
index f391a24a1b44..4db1dc468a11 100644
--- a/drivers/char/moxa.c
+++ b/drivers/char/moxa.c
@@ -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) )