提交 a58e00e7 编写于 作者: J Jesper Juhl 提交者: Linus Torvalds

[PATCH] Decrease number of pointer derefs in jsm_tty.c

Decrease the number of pointer derefs in drivers/serial/jsm/jsm_tty.c

Benefits of the patch:
 - Fewer pointer dereferences should make the code slightly faster.
 - Size of generated code is smaller
 - Improved readability
Signed-off-by: NJesper Juhl <jesper.juhl@gmail.com>
Acked-by: N"V. ANANDA KRISHNAN" <mansarov@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
上级 a244e169
......@@ -142,12 +142,14 @@ static void jsm_tty_send_xchar(struct uart_port *port, char ch)
{
unsigned long lock_flags;
struct jsm_channel *channel = (struct jsm_channel *)port;
struct termios *termios;
spin_lock_irqsave(&port->lock, lock_flags);
if (ch == port->info->tty->termios->c_cc[VSTART])
termios = port->info->tty->termios;
if (ch == termios->c_cc[VSTART])
channel->ch_bd->bd_ops->send_start_character(channel);
if (ch == port->info->tty->termios->c_cc[VSTOP])
if (ch == termios->c_cc[VSTOP])
channel->ch_bd->bd_ops->send_stop_character(channel);
spin_unlock_irqrestore(&port->lock, lock_flags);
}
......@@ -178,6 +180,7 @@ static int jsm_tty_open(struct uart_port *port)
struct jsm_board *brd;
int rc = 0;
struct jsm_channel *channel = (struct jsm_channel *)port;
struct termios *termios;
/* Get board pointer from our array of majors we have allocated */
brd = channel->ch_bd;
......@@ -239,12 +242,13 @@ static int jsm_tty_open(struct uart_port *port)
channel->ch_cached_lsr = 0;
channel->ch_stops_sent = 0;
channel->ch_c_cflag = port->info->tty->termios->c_cflag;
channel->ch_c_iflag = port->info->tty->termios->c_iflag;
channel->ch_c_oflag = port->info->tty->termios->c_oflag;
channel->ch_c_lflag = port->info->tty->termios->c_lflag;
channel->ch_startc = port->info->tty->termios->c_cc[VSTART];
channel->ch_stopc = port->info->tty->termios->c_cc[VSTOP];
termios = port->info->tty->termios;
channel->ch_c_cflag = termios->c_cflag;
channel->ch_c_iflag = termios->c_iflag;
channel->ch_c_oflag = termios->c_oflag;
channel->ch_c_lflag = termios->c_lflag;
channel->ch_startc = termios->c_cc[VSTART];
channel->ch_stopc = termios->c_cc[VSTOP];
/* Tell UART to init itself */
brd->bd_ops->uart_init(channel);
......@@ -784,6 +788,7 @@ static void jsm_carrier(struct jsm_channel *ch)
void jsm_check_queue_flow_control(struct jsm_channel *ch)
{
struct board_ops *bd_ops = ch->ch_bd->bd_ops;
int qleft = 0;
/* Store how much space we have left in the queue */
......@@ -809,7 +814,7 @@ void jsm_check_queue_flow_control(struct jsm_channel *ch)
/* HWFLOW */
if (ch->ch_c_cflag & CRTSCTS) {
if(!(ch->ch_flags & CH_RECEIVER_OFF)) {
ch->ch_bd->bd_ops->disable_receiver(ch);
bd_ops->disable_receiver(ch);
ch->ch_flags |= (CH_RECEIVER_OFF);
jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
"Internal queue hit hilevel mark (%d)! Turning off interrupts.\n",
......@@ -819,7 +824,7 @@ void jsm_check_queue_flow_control(struct jsm_channel *ch)
/* SWFLOW */
else if (ch->ch_c_iflag & IXOFF) {
if (ch->ch_stops_sent <= MAX_STOPS_SENT) {
ch->ch_bd->bd_ops->send_stop_character(ch);
bd_ops->send_stop_character(ch);
ch->ch_stops_sent++;
jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
"Sending stop char! Times sent: %x\n", ch->ch_stops_sent);
......@@ -846,7 +851,7 @@ void jsm_check_queue_flow_control(struct jsm_channel *ch)
/* HWFLOW */
if (ch->ch_c_cflag & CRTSCTS) {
if (ch->ch_flags & CH_RECEIVER_OFF) {
ch->ch_bd->bd_ops->enable_receiver(ch);
bd_ops->enable_receiver(ch);
ch->ch_flags &= ~(CH_RECEIVER_OFF);
jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
"Internal queue hit lowlevel mark (%d)! Turning on interrupts.\n",
......@@ -856,7 +861,7 @@ void jsm_check_queue_flow_control(struct jsm_channel *ch)
/* SWFLOW */
else if (ch->ch_c_iflag & IXOFF && ch->ch_stops_sent) {
ch->ch_stops_sent = 0;
ch->ch_bd->bd_ops->send_start_character(ch);
bd_ops->send_start_character(ch);
jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "Sending start char!\n");
}
}
......
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