Re: [PATCH 10/16] TTY: cleanup tty->hw_stopped uses

Peter Hurley
2013-03-08T14:39:35Z

On Thu, 2013-03-07 at 13:12 +0100, Jiri Slaby wrote:
> tty->hw_stopped is set only by drivers to remember HW state. If it is
> never set to 1 in a particular driver, there is no need to check it in
> the driver at all. Remove such checks.
>
> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
> ---
> arch/ia64/hp/sim/simserial.c | 16 +++-------------
> drivers/isdn/i4l/isdn_tty.c | 3 ---
> drivers/net/caif/caif_serial.c | 1 -
> drivers/tty/rocket.c | 19 ++++++++-----------
> drivers/tty/serial/68328serial.c | 9 +++------
> drivers/tty/serial/arc_uart.c | 2 +-
> drivers/tty/serial/crisv10.c | 12 ++----------
> 7 files changed, 17 insertions(+), 45 deletions(-)
>
> diff --git a/arch/ia64/hp/sim/simserial.c b/arch/ia64/hp/sim/simserial.c
> index da2f319..e70cade 100644
> --- a/arch/ia64/hp/sim/simserial.c
> +++ b/arch/ia64/hp/sim/simserial.c
> @@ -142,8 +142,7 @@ static void transmit_chars(struct tty_struct *tty, struct serial_state *info,
> goto out;
> }
>
> - if (info->xmit.head == info->xmit.tail || tty->stopped ||
> - tty->hw_stopped) {
> + if (info->xmit.head == info->xmit.tail || tty->stopped) {
> #ifdef SIMSERIAL_DEBUG
> printk("transmit_chars: head=%d, tail=%d, stopped=%d\n",
> info->xmit.head, info->xmit.tail, tty->stopped);
> @@ -181,7 +180,7 @@ static void rs_flush_chars(struct tty_struct *tty)
> struct serial_state *info = tty->driver_data;
>
> if (info->xmit.head == info->xmit.tail || tty->stopped ||
> - tty->hw_stopped || !info->xmit.buf)
> + !info->xmit.buf)
> return;
>
> transmit_chars(tty, info, NULL);
> @@ -217,7 +216,7 @@ static int rs_write(struct tty_struct * tty,
> * Hey, we transmit directly from here in our case
> */
> if (CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE) &&
> - !tty->stopped && !tty->hw_stopped)
> + !tty->stopped)
> transmit_chars(tty, info, NULL);
>
> return ret;
> @@ -325,14 +324,6 @@ static int rs_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
>
> #define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
>
> -static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
> -{
> - /* Handle turning off CRTSCTS */
> - if ((old_termios->c_cflag & CRTSCTS) &&
> - !(tty->termios.c_cflag & CRTSCTS)) {
> - tty->hw_stopped = 0;
> - }
> -}
> /*
> * This routine will shutdown a serial port; interrupts are disabled, and
> * DTR is dropped if the hangup on close termio flag is on.
> @@ -481,7 +472,6 @@ static const struct tty_operations hp_ops = {
> .throttle = rs_throttle,
> .unthrottle = rs_unthrottle,
> .send_xchar = rs_send_xchar,
> - .set_termios = rs_set_termios,
> .hangup = rs_hangup,
> .proc_fops = &rs_proc_fops,
> };
> diff --git a/drivers/isdn/i4l/isdn_tty.c b/drivers/isdn/i4l/isdn_tty.c
> index d8a7d83..2210766 100644
> --- a/drivers/isdn/i4l/isdn_tty.c
> +++ b/drivers/isdn/i4l/isdn_tty.c
> @@ -1470,9 +1470,6 @@ isdn_tty_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
> tty->termios.c_ospeed == old_termios->c_ospeed)
> return;
> isdn_tty_change_speed(info);
> - if ((old_termios->c_cflag & CRTSCTS) &&
> - !(tty->termios.c_cflag & CRTSCTS))
> - tty->hw_stopped = 0;
> }
> }
>
> diff --git a/drivers/net/caif/caif_serial.c b/drivers/net/caif/caif_serial.c
> index 666891a..d1bf0ff 100644
> --- a/drivers/net/caif/caif_serial.c
> +++ b/drivers/net/caif/caif_serial.c
> @@ -88,7 +88,6 @@ static inline void update_tty_status(struct ser_device *ser)
> {
> ser->tty_status =
> ser->tty->stopped << 5 |
> - ser->tty->hw_stopped << 4 |
> ser->tty->flow_stopped << 3 |
> ser->tty->packet << 2 |
> ser->tty->port->low_latency << 1 |

I would maybe leave this with a code comment instead.

ser->tty->hw_stopped << 4 | /* hw_stopped is not used by tty layer */

> diff --git a/drivers/tty/rocket.c b/drivers/tty/rocket.c
> index bbffd7a..f5abc28 100644
> --- a/drivers/tty/rocket.c
> +++ b/drivers/tty/rocket.c
> @@ -449,7 +449,7 @@ static void rp_do_transmit(struct r_port *info)
>
> /* Loop sending data to FIFO until done or FIFO full */
> while (1) {
> - if (tty->stopped || tty->hw_stopped)
> + if (tty->stopped)
> break;
> c = min(info->xmit_fifo_room, info->xmit_cnt);
> c = min(c, XMIT_BUF_SIZE - info->xmit_tail);
> @@ -1106,15 +1106,12 @@ static void rp_set_termios(struct tty_struct *tty,
>
> /* Handle transition away from B0 status */
> if (!(old_termios->c_cflag & CBAUD) && (tty->termios.c_cflag & CBAUD)) {
> - if (!tty->hw_stopped || !(tty->termios.c_cflag & CRTSCTS))
> - sSetRTS(cp);
> + sSetRTS(cp);

Terrible original logic there.

> sSetDTR(cp);
> }
>
> - if ((old_termios->c_cflag & CRTSCTS) && !(tty->termios.c_cflag & CRTSCTS)) {
> - tty->hw_stopped = 0;
> + if ((old_termios->c_cflag & CRTSCTS) && !(tty->termios.c_cflag & CRTSCTS))
> rp_start(tty);
> - }
> }
>
> static int rp_break(struct tty_struct *tty, int break_state)
> @@ -1570,10 +1567,10 @@ static int rp_put_char(struct tty_struct *tty, unsigned char ch)
> spin_lock_irqsave(&info->slock, flags);
> cp = &info->channel;
>
> - if (!tty->stopped && !tty->hw_stopped && info->xmit_fifo_room == 0)
> + if (!tty->stopped && info->xmit_fifo_room == 0)
> info->xmit_fifo_room = TXFIFO_SIZE - sGetTxCnt(cp);
>
> - if (tty->stopped || tty->hw_stopped || info->xmit_fifo_room == 0 || info->xmit_cnt != 0) {
> + if (tty->stopped || info->xmit_fifo_room == 0 || info->xmit_cnt != 0) {
> info->xmit_buf[info->xmit_head++] = ch;
> info->xmit_head &= XMIT_BUF_SIZE - 1;
> info->xmit_cnt++;
> @@ -1614,14 +1611,14 @@ static int rp_write(struct tty_struct *tty,
> #endif
> cp = &info->channel;
>
> - if (!tty->stopped && !tty->hw_stopped && info->xmit_fifo_room < count)
> + if (!tty->stopped && info->xmit_fifo_room < count)
> info->xmit_fifo_room = TXFIFO_SIZE - sGetTxCnt(cp);
>
> /*
> * If the write queue for the port is empty, and there is FIFO space, stuff bytes
> * into FIFO. Use the write queue for temp storage.
> */
> - if (!tty->stopped && !tty->hw_stopped && info->xmit_cnt == 0 && info->xmit_fifo_room > 0) {
> + if (!tty->stopped && info->xmit_cnt == 0 && info->xmit_fifo_room > 0) {
> c = min(count, info->xmit_fifo_room);
> b = buf;
>
> @@ -1669,7 +1666,7 @@ static int rp_write(struct tty_struct *tty,
> retval += c;
> }
>
> - if ((retval > 0) && !tty->stopped && !tty->hw_stopped)
> + if ((retval > 0) && !tty->stopped)
> set_bit((info->aiop * 8) + info->chan, (void *) &xmit_flags[info->board]);
>
> end:
> diff --git a/drivers/tty/serial/68328serial.c b/drivers/tty/serial/68328serial.c
> index 4939947..ef2e08e 100644
> --- a/drivers/tty/serial/68328serial.c
> +++ b/drivers/tty/serial/68328serial.c
> @@ -630,8 +630,7 @@ static void rs_flush_chars(struct tty_struct *tty)
> /* Enable transmitter */
> local_irq_save(flags);
>
> - if (info->xmit_cnt <= 0 || tty->stopped || tty->hw_stopped ||
> - !info->xmit_buf) {
> + if (info->xmit_cnt <= 0 || tty->stopped || !info->xmit_buf) {
> local_irq_restore(flags);
> return;
> }
> @@ -697,7 +696,7 @@ static int rs_write(struct tty_struct * tty,
> total += c;
> }
>
> - if (info->xmit_cnt && !tty->stopped && !tty->hw_stopped) {
> + if (info->xmit_cnt && !tty->stopped) {
> /* Enable transmitter */
> local_irq_disable();
> #ifndef USE_INTS
> @@ -978,10 +977,8 @@ static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
> change_speed(info, tty);
>
> if ((old_termios->c_cflag & CRTSCTS) &&
> - !(tty->termios.c_cflag & CRTSCTS)) {
> - tty->hw_stopped = 0;
> + !(tty->termios.c_cflag & CRTSCTS))
> rs_start(tty);
> - }
>
> }
>
> diff --git a/drivers/tty/serial/arc_uart.c b/drivers/tty/serial/arc_uart.c
> index d97e194..cbf1d15 100644
> --- a/drivers/tty/serial/arc_uart.c
> +++ b/drivers/tty/serial/arc_uart.c
> @@ -162,7 +162,7 @@ static unsigned int arc_serial_tx_empty(struct uart_port *port)
> /*
> * Driver internal routine, used by both tty(serial core) as well as tx-isr
> * -Called under spinlock in either cases
> - * -also tty->stopped / tty->hw_stopped has already been checked
> + * -also tty->stopped has already been checked
> * = by uart_start( ) before calling us
> * = tx_ist checks that too before calling
> */
> diff --git a/drivers/tty/serial/crisv10.c b/drivers/tty/serial/crisv10.c
> index 5f37c31..50f56f3 100644
> --- a/drivers/tty/serial/crisv10.c
> +++ b/drivers/tty/serial/crisv10.c
> @@ -2534,8 +2534,7 @@ static void handle_ser_tx_interrupt(struct e100_serial *info)
> }
> /* Normal char-by-char interrupt */
> if (info->xmit.head == info->xmit.tail
> - || info->port.tty->stopped
> - || info->port.tty->hw_stopped) {
> + || info->port.tty->stopped) {
> DFLOW(DEBUG_LOG(info->line, "tx_int: stopped %i\n",
> info->port.tty->stopped));
> e100_disable_serial_tx_ready_irq(info);
> @@ -3098,7 +3097,6 @@ rs_flush_chars(struct tty_struct *tty)
> if (info->tr_running ||
> info->xmit.head == info->xmit.tail ||
> tty->stopped ||
> - tty->hw_stopped ||
> !info->xmit.buf)
> return;
>
> @@ -3176,7 +3174,6 @@ static int rs_raw_write(struct tty_struct *tty,
>
> if (info->xmit.head != info->xmit.tail &&
> !tty->stopped &&
> - !tty->hw_stopped &&
> !info->tr_running) {
> start_transmit(info);
> }
> @@ -3733,10 +3730,8 @@ rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
>
> /* Handle turning off CRTSCTS */
> if ((old_termios->c_cflag & CRTSCTS) &&
> - !(tty->termios.c_cflag & CRTSCTS)) {
> - tty->hw_stopped = 0;
> + !(tty->termios.c_cflag & CRTSCTS))
> rs_start(tty);
> - }
>
> }
>
> @@ -4256,9 +4251,6 @@ static void seq_line_info(struct seq_file *m, struct e100_serial *info)
> if (info->port.tty->stopped)
> seq_printf(m, " stopped:%i",
> (int)info->port.tty->stopped);
> - if (info->port.tty->hw_stopped)
> - seq_printf(m, " hw_stopped:%i",
> - (int)info->port.tty->hw_stopped);

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