From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932692AbVLHWgX (ORCPT ); Thu, 8 Dec 2005 17:36:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932691AbVLHWgW (ORCPT ); Thu, 8 Dec 2005 17:36:22 -0500 Received: from uproxy.gmail.com ([66.249.92.196]:20082 "EHLO uproxy.gmail.com") by vger.kernel.org with ESMTP id S932689AbVLHWgS (ORCPT ); Thu, 8 Dec 2005 17:36:18 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:from:to:subject:date:user-agent:cc:mime-version:content-disposition:content-type:content-transfer-encoding:message-id; b=daiJO69H9xaEfi38FdaoWfKxohUNe77JlqxoUG46AgwvYkwMgktYS609nAnk8akXuZx3tInvoaxDU62t3s5cRHxT64DavWNmmD3sx8FYLwWgxga2O/vFjLQzgR+xl6rY02sUlIRUrrR64T0U1BMtIFtxc5vD9yZc6Uo7bKw42kc= From: Jesper Juhl To: Linux Kernel Mailing List Subject: [PATCH] Decrease number of pointer derefs in jsm_tty.c Date: Thu, 8 Dec 2005 23:36:45 +0100 User-Agent: KMail/1.9 Cc: Scott H Kilau , Wendy Xiong , Alan Cox , Andrew Morton , Jesper Juhl MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Message-Id: <200512082336.46198.jesper.juhl@gmail.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, Here's a small patch to 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 Please consider applying. Signed-off-by: Jesper Juhl --- drivers/serial/jsm/jsm_tty.c | 29 +++++++++++++++++------------ 1 files changed, 17 insertions(+), 12 deletions(-) orig: text data bss dec hex filename 7937 80 0 8017 1f51 drivers/serial/jsm/jsm_tty.o patched: text data bss dec hex filename 7874 80 0 7954 1f12 drivers/serial/jsm/jsm_tty.o --- linux-2.6.15-rc5-git1-orig/drivers/serial/jsm/jsm_tty.c 2005-10-28 02:02:08.000000000 +0200 +++ linux-2.6.15-rc5-git1/drivers/serial/jsm/jsm_tty.c 2005-12-08 22:45:48.000000000 +0100 @@ -140,12 +140,14 @@ static void jsm_tty_send_xchar(struct ua { 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); } @@ -176,6 +178,7 @@ static int jsm_tty_open(struct uart_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; @@ -237,12 +240,13 @@ static int jsm_tty_open(struct uart_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); @@ -863,6 +867,7 @@ static void jsm_carrier(struct jsm_chann 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 */ @@ -888,7 +893,7 @@ void jsm_check_queue_flow_control(struct /* 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", @@ -898,7 +903,7 @@ void jsm_check_queue_flow_control(struct /* 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); @@ -925,7 +930,7 @@ void jsm_check_queue_flow_control(struct /* 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", @@ -935,7 +940,7 @@ void jsm_check_queue_flow_control(struct /* 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"); } }