[PATCH] char: kill unneeded memsets

char, another tmp_buf cleanup

No need to allocate one page as a side buffer.  It's no more used.  Clean this
(de)allocs of this useless memory pages in char subtree.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 1 insertions, 29 deletions

diff --git a/drivers/char/amiserial.c b/drivers/char/amiserial.c
index d0e92ed0a36..486f97c3f4e 100644
--- a/drivers/char/amiserial.c
+++ b/drivers/char/amiserial.c
@@ -112,17 +112,6 @@ static struct serial_state rs_table[1];
 
 #define NR_PORTS ARRAY_SIZE(rs_table)
 
-/*
- * 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.
- */
-static unsigned char *tmp_buf;
-
 #include <asm/uaccess.h>
 
 #define serial_isroot() (capable(CAP_SYS_ADMIN))
@@ -912,7 +901,7 @@ static int rs_write(struct tty_struct * tty, const unsigned char *buf, int count
         if (serial_paranoia_check(info, tty->name, "rs_write"))
                 return 0;
 
-        if (!info->xmit.buf || !tmp_buf)
+        if (!info->xmit.buf)
                 return 0;
 
         local_save_flags(flags);
@@ -1778,7 +1767,6 @@ static int rs_open(struct tty_struct *tty, struct file * filp)
 {
         struct async_struct     *info;
         int                     retval, line;
-        unsigned long           page;
 
         line = tty->index;
         if ((line < 0) || (line >= NR_PORTS)) {
@@ -1798,17 +1786,6 @@ static int rs_open(struct tty_struct *tty, struct file * filp)
 #endif
         info->tty->low_latency = (info->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
 
-        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
          */
@@ -2090,11 +2067,6 @@ static __exit void rs_exit(void)
           kfree(info);
         }
 
-        if (tmp_buf) {
-                free_page((unsigned long) tmp_buf);
-                tmp_buf = NULL;
-        }
-
         release_mem_region(CUSTOM_PHYSADDR+0x30, 4);
 }