From c5f4644e6c8ba21666128603e4e92544d3cd740d Mon Sep 17 00:00:00 2001 From: Russell King Date: Wed, 29 Jun 2005 09:42:38 +0100 Subject: [PATCH] Serial: Adjust serial locking This patch changes the way serial ports are locked when getting modem status. This change is necessary because we will need to atomically read the modem status and take action depending on the CTS status. Signed-off-by: Russell King --- drivers/serial/8250.c | 3 --- drivers/serial/au1x00_uart.c | 3 --- drivers/serial/ip22zilog.c | 13 +++++++------ drivers/serial/mpsc.c | 3 --- drivers/serial/pmac_zilog.c | 4 ++-- drivers/serial/pxa.c | 3 --- drivers/serial/serial_core.c | 11 ++++++++++- drivers/serial/serial_txx9.c | 3 --- drivers/serial/sunsab.c | 7 +------ drivers/serial/sunsu.c | 3 --- drivers/serial/sunzilog.c | 13 +++++++------ 11 files changed, 27 insertions(+), 39 deletions(-) (limited to 'drivers') diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index 34e75bc8f4..b53b53bb14 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -1376,13 +1376,10 @@ static unsigned int serial8250_tx_empty(struct uart_port *port) static unsigned int serial8250_get_mctrl(struct uart_port *port) { struct uart_8250_port *up = (struct uart_8250_port *)port; - unsigned long flags; unsigned char status; unsigned int ret; - spin_lock_irqsave(&up->port.lock, flags); status = serial_in(up, UART_MSR); - spin_unlock_irqrestore(&up->port.lock, flags); ret = 0; if (status & UART_MSR_DCD) diff --git a/drivers/serial/au1x00_uart.c b/drivers/serial/au1x00_uart.c index 5400dc2c08..6104aeef12 100644 --- a/drivers/serial/au1x00_uart.c +++ b/drivers/serial/au1x00_uart.c @@ -556,13 +556,10 @@ static unsigned int serial8250_tx_empty(struct uart_port *port) static unsigned int serial8250_get_mctrl(struct uart_port *port) { struct uart_8250_port *up = (struct uart_8250_port *)port; - unsigned long flags; unsigned char status; unsigned int ret; - spin_lock_irqsave(&up->port.lock, flags); status = serial_in(up, UART_MSR); - spin_unlock_irqrestore(&up->port.lock, flags); ret = 0; if (status & UART_MSR_DCD) diff --git a/drivers/serial/ip22zilog.c b/drivers/serial/ip22zilog.c index 3ea46c069f..ea5bf4d4da 100644 --- a/drivers/serial/ip22zilog.c +++ b/drivers/serial/ip22zilog.c @@ -518,27 +518,28 @@ static irqreturn_t ip22zilog_interrupt(int irq, void *dev_id, struct pt_regs *re static __inline__ unsigned char ip22zilog_read_channel_status(struct uart_port *port) { struct zilog_channel *channel; - unsigned long flags; unsigned char status; - spin_lock_irqsave(&port->lock, flags); - channel = ZILOG_CHANNEL_FROM_PORT(port); status = readb(&channel->control); ZSDELAY(); - spin_unlock_irqrestore(&port->lock, flags); - return status; } /* The port lock is not held. */ static unsigned int ip22zilog_tx_empty(struct uart_port *port) { + unsigned long flags; unsigned char status; unsigned int ret; + spin_lock_irqsave(&port->lock, flags); + status = ip22zilog_read_channel_status(port); + + spin_unlock_irqrestore(&port->lock, flags); + if (status & Tx_BUF_EMP) ret = TIOCSER_TEMT; else @@ -547,7 +548,7 @@ static unsigned int ip22zilog_tx_empty(struct uart_port *port) return ret; } -/* The port lock is not held. */ +/* The port lock is held and interrupts are disabled. */ static unsigned int ip22zilog_get_mctrl(struct uart_port *port) { unsigned char status; diff --git a/drivers/serial/mpsc.c b/drivers/serial/mpsc.c index a2a6433180..e43276c6a9 100644 --- a/drivers/serial/mpsc.c +++ b/drivers/serial/mpsc.c @@ -1058,12 +1058,9 @@ mpsc_get_mctrl(struct uart_port *port) { struct mpsc_port_info *pi = (struct mpsc_port_info *)port; u32 mflags, status; - ulong iflags; - spin_lock_irqsave(&pi->port.lock, iflags); status = (pi->mirror_regs) ? pi->MPSC_CHR_10_m : readl(pi->mpsc_base + MPSC_CHR_10); - spin_unlock_irqrestore(&pi->port.lock, iflags); mflags = 0; if (status & 0x1) diff --git a/drivers/serial/pmac_zilog.c b/drivers/serial/pmac_zilog.c index 85abd8a045..1c9f716171 100644 --- a/drivers/serial/pmac_zilog.c +++ b/drivers/serial/pmac_zilog.c @@ -604,7 +604,7 @@ static void pmz_set_mctrl(struct uart_port *port, unsigned int mctrl) /* * Get Modem Control bits (only the input ones, the core will * or that with a cached value of the control ones) - * The port lock is not held. + * The port lock is held and interrupts are disabled. */ static unsigned int pmz_get_mctrl(struct uart_port *port) { @@ -615,7 +615,7 @@ static unsigned int pmz_get_mctrl(struct uart_port *port) if (ZS_IS_ASLEEP(uap) || uap->node == NULL) return 0; - status = pmz_peek_status(to_pmz(port)); + status = read_zsreg(uap, R0); ret = 0; if (status & DCD) diff --git a/drivers/serial/pxa.c b/drivers/serial/pxa.c index 08b08d6ae9..461c81c932 100644 --- a/drivers/serial/pxa.c +++ b/drivers/serial/pxa.c @@ -274,14 +274,11 @@ static unsigned int serial_pxa_tx_empty(struct uart_port *port) static unsigned int serial_pxa_get_mctrl(struct uart_port *port) { struct uart_pxa_port *up = (struct uart_pxa_port *)port; - unsigned long flags; unsigned char status; unsigned int ret; return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR; - spin_lock_irqsave(&up->port.lock, flags); status = serial_in(up, UART_MSR); - spin_unlock_irqrestore(&up->port.lock, flags); ret = 0; if (status & UART_MSR_DCD) diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c index 36b1ae083f..f5ce58d051 100644 --- a/drivers/serial/serial_core.c +++ b/drivers/serial/serial_core.c @@ -828,7 +828,10 @@ static int uart_tiocmget(struct tty_struct *tty, struct file *file) if ((!file || !tty_hung_up_p(file)) && !(tty->flags & (1 << TTY_IO_ERROR))) { result = port->mctrl; + + spin_lock_irq(&port->lock); result |= port->ops->get_mctrl(port); + spin_unlock_irq(&port->lock); } up(&state->sem); @@ -1369,6 +1372,7 @@ uart_block_til_ready(struct file *filp, struct uart_state *state) DECLARE_WAITQUEUE(wait, current); struct uart_info *info = state->info; struct uart_port *port = state->port; + unsigned int mctrl; info->blocked_open++; state->count--; @@ -1416,7 +1420,10 @@ uart_block_til_ready(struct file *filp, struct uart_state *state) * and wait for the carrier to indicate that the * modem is ready for us. */ - if (port->ops->get_mctrl(port) & TIOCM_CAR) + spin_lock_irq(&port->lock); + mctrl = port->ops->get_mctrl(port); + spin_unlock_irq(&port->lock); + if (mctrl & TIOCM_CAR) break; up(&state->sem); @@ -1618,7 +1625,9 @@ static int uart_line_info(char *buf, struct uart_driver *drv, int i) if(capable(CAP_SYS_ADMIN)) { + spin_lock_irq(&port->lock); status = port->ops->get_mctrl(port); + spin_unlock_irq(&port->lock); ret += sprintf(buf + ret, " tx:%d rx:%d", port->icount.tx, port->icount.rx); diff --git a/drivers/serial/serial_txx9.c b/drivers/serial/serial_txx9.c index 3f1051a4a1..d085030df7 100644 --- a/drivers/serial/serial_txx9.c +++ b/drivers/serial/serial_txx9.c @@ -442,13 +442,10 @@ static unsigned int serial_txx9_tx_empty(struct uart_port *port) static unsigned int serial_txx9_get_mctrl(struct uart_port *port) { struct uart_txx9_port *up = (struct uart_txx9_port *)port; - unsigned long flags; unsigned int ret; - spin_lock_irqsave(&up->port.lock, flags); ret = ((sio_in(up, TXX9_SIFLCR) & TXX9_SIFLCR_RTSSC) ? 0 : TIOCM_RTS) | ((sio_in(up, TXX9_SICISR) & TXX9_SICISR_CTSS) ? 0 : TIOCM_CTS); - spin_unlock_irqrestore(&up->port.lock, flags); return ret; } diff --git a/drivers/serial/sunsab.c b/drivers/serial/sunsab.c index 10e2990a40..8d19888075 100644 --- a/drivers/serial/sunsab.c +++ b/drivers/serial/sunsab.c @@ -426,18 +426,15 @@ static void sunsab_set_mctrl(struct uart_port *port, unsigned int mctrl) sunsab_tx_idle(up); } -/* port->lock is not held. */ +/* port->lock is held by caller and interrupts are disabled. */ static unsigned int sunsab_get_mctrl(struct uart_port *port) { struct uart_sunsab_port *up = (struct uart_sunsab_port *) port; - unsigned long flags; unsigned char val; unsigned int result; result = 0; - spin_lock_irqsave(&up->port.lock, flags); - val = readb(&up->regs->r.pvr); result |= (val & up->pvr_dsr_bit) ? 0 : TIOCM_DSR; @@ -447,8 +444,6 @@ static unsigned int sunsab_get_mctrl(struct uart_port *port) val = readb(&up->regs->r.star); result |= (val & SAB82532_STAR_CTS) ? TIOCM_CTS : 0; - spin_unlock_irqrestore(&up->port.lock, flags); - return result; } diff --git a/drivers/serial/sunsu.c b/drivers/serial/sunsu.c index ddc97c905e..d57a3553ae 100644 --- a/drivers/serial/sunsu.c +++ b/drivers/serial/sunsu.c @@ -572,13 +572,10 @@ static unsigned int sunsu_tx_empty(struct uart_port *port) static unsigned int sunsu_get_mctrl(struct uart_port *port) { struct uart_sunsu_port *up = (struct uart_sunsu_port *) port; - unsigned long flags; unsigned char status; unsigned int ret; - spin_lock_irqsave(&up->port.lock, flags); status = serial_in(up, UART_MSR); - spin_unlock_irqrestore(&up->port.lock, flags); ret = 0; if (status & UART_MSR_DCD) diff --git a/drivers/serial/sunzilog.c b/drivers/serial/sunzilog.c index 8e65206d3d..bff42a7b89 100644 --- a/drivers/serial/sunzilog.c +++ b/drivers/serial/sunzilog.c @@ -610,27 +610,28 @@ static irqreturn_t sunzilog_interrupt(int irq, void *dev_id, struct pt_regs *reg static __inline__ unsigned char sunzilog_read_channel_status(struct uart_port *port) { struct zilog_channel __iomem *channel; - unsigned long flags; unsigned char status; - spin_lock_irqsave(&port->lock, flags); - channel = ZILOG_CHANNEL_FROM_PORT(port); status = sbus_readb(&channel->control); ZSDELAY(); - spin_unlock_irqrestore(&port->lock, flags); - return status; } /* The port lock is not held. */ static unsigned int sunzilog_tx_empty(struct uart_port *port) { + unsigned long flags; unsigned char status; unsigned int ret; + spin_lock_irqsave(&port->lock, flags); + status = sunzilog_read_channel_status(port); + + spin_unlock_irqrestore(&port->lock, flags); + if (status & Tx_BUF_EMP) ret = TIOCSER_TEMT; else @@ -639,7 +640,7 @@ static unsigned int sunzilog_tx_empty(struct uart_port *port) return ret; } -/* The port lock is not held. */ +/* The port lock is held and interrupts are disabled. */ static unsigned int sunzilog_get_mctrl(struct uart_port *port) { unsigned char status; -- cgit v1.2.2 From 0dd7a1aed7c34a39917c4faf75b4230c169e809b Mon Sep 17 00:00:00 2001 From: Russell King Date: Wed, 29 Jun 2005 18:40:53 +0100 Subject: [PATCH] Serial: Check status of CTS when using flow control Fix bugme #4712: read the CTS status and set hw_stopped if CTS is not active when opening the port and/or enabling CRTSCTS Thanks to Stefan Wolff for spotting this problem. Signed-off-by: Russell King --- drivers/serial/serial_core.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'drivers') diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c index f5ce58d051..139863a787 100644 --- a/drivers/serial/serial_core.c +++ b/drivers/serial/serial_core.c @@ -182,6 +182,13 @@ static int uart_startup(struct uart_state *state, int init_hw) uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR); } + if (info->flags & UIF_CTS_FLOW) { + spin_lock_irq(&port->lock); + if (!(port->ops->get_mctrl(port) & TIOCM_CTS)) + info->tty->hw_stopped = 1; + spin_unlock_irq(&port->lock); + } + info->flags |= UIF_INITIALIZED; clear_bit(TTY_IO_ERROR, &info->tty->flags); @@ -1134,6 +1141,16 @@ static void uart_set_termios(struct tty_struct *tty, struct termios *old_termios spin_unlock_irqrestore(&state->port->lock, flags); } + /* Handle turning on CRTSCTS */ + if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) { + spin_lock_irqsave(&state->port->lock, flags); + if (!(state->port->ops->get_mctrl(state->port) & TIOCM_CTS)) { + tty->hw_stopped = 1; + state->port->ops->stop_tx(state->port, 0); + } + spin_unlock_irqrestore(&state->port->lock, flags); + } + #if 0 /* * No need to wake up processes in open wait, since they -- cgit v1.2.2 From e763b90c41563a0f8258d379fe71a9a1f1fa5445 Mon Sep 17 00:00:00 2001 From: Russell King Date: Wed, 29 Jun 2005 18:41:51 +0100 Subject: [PATCH] Serial: Disable OX950 transmitter for flow control Disable the transmitter whenever we want to prevent characters being transmitted by flow control. However, if we run out of characters to send and want to only disable the TX interrupt, allow that scenario. Signed-off-by: Russell King --- drivers/serial/8250.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) (limited to 'drivers') diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index b53b53bb14..429994d5bc 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -993,21 +993,24 @@ static void autoconfig_irq(struct uart_8250_port *up) up->port.irq = (irq > 0) ? irq : 0; } +static inline void __stop_tx(struct uart_8250_port *p) +{ + if (p->ier & UART_IER_THRI) { + p->ier &= ~UART_IER_THRI; + serial_out(p, UART_IER, p->ier); + } +} + static void serial8250_stop_tx(struct uart_port *port, unsigned int tty_stop) { struct uart_8250_port *up = (struct uart_8250_port *)port; - if (up->ier & UART_IER_THRI) { - up->ier &= ~UART_IER_THRI; - serial_out(up, UART_IER, up->ier); - } + __stop_tx(up); /* - * We only do this from uart_stop - if we run out of - * characters to send, we don't want to prevent the - * FIFO from emptying. + * We really want to stop the transmitter from sending. */ - if (up->port.type == PORT_16C950 && tty_stop) { + if (up->port.type == PORT_16C950) { up->acr |= UART_ACR_TXDIS; serial_icr_write(up, UART_ACR, up->acr); } @@ -1031,10 +1034,11 @@ static void serial8250_start_tx(struct uart_port *port, unsigned int tty_start) transmit_chars(up); } } + /* - * We only do this from uart_start + * Re-enable the transmitter if we disabled it. */ - if (tty_start && up->port.type == PORT_16C950) { + if (up->port.type == PORT_16C950 && up->acr & UART_ACR_TXDIS) { up->acr &= ~UART_ACR_TXDIS; serial_icr_write(up, UART_ACR, up->acr); } @@ -1155,7 +1159,7 @@ static _INLINE_ void transmit_chars(struct uart_8250_port *up) return; } if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) { - serial8250_stop_tx(&up->port, 0); + __stop_tx(up); return; } @@ -1174,7 +1178,7 @@ static _INLINE_ void transmit_chars(struct uart_8250_port *up) DEBUG_INTR("THRE..."); if (uart_circ_empty(xmit)) - serial8250_stop_tx(&up->port, 0); + __stop_tx(up); } static _INLINE_ void check_modem_status(struct uart_8250_port *up) -- cgit v1.2.2 From 026d02a236f429eb61a1277166bd425f8514c431 Mon Sep 17 00:00:00 2001 From: Russell King Date: Wed, 29 Jun 2005 18:45:19 +0100 Subject: [PATCH] Serial: Split 8250 port table (part 2) Remove legacy ISA serial ports for Accent, Boca, Fourport, Hub6 and MCA from the architecture specific serial.h include. The only ports which remain in asm-*/serial.h are the platform specific entries. These should really be converted by platform maintainers to use a platform device, such as can be found in arch/arm/mach-footbridge/isa.c Signed-off-by: Russell King --- drivers/serial/8250.c | 2 +- drivers/serial/Kconfig | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index 429994d5bc..9224fc3184 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -105,7 +105,7 @@ static struct old_serial_port old_serial_port[] = { SERIAL_PORT_DFNS /* defined in asm/serial.h */ }; -#define UART_NR (ARRAY_SIZE(old_serial_port) + CONFIG_SERIAL_8250_NR_UARTS) +#define UART_NR CONFIG_SERIAL_8250_NR_UARTS #ifdef CONFIG_SERIAL_8250_RSA diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig index e879bce160..e0d0a470dd 100644 --- a/drivers/serial/Kconfig +++ b/drivers/serial/Kconfig @@ -86,7 +86,7 @@ config SERIAL_8250_ACPI namespace, say Y here. If unsure, say N. config SERIAL_8250_NR_UARTS - int "Maximum number of non-legacy 8250/16550 serial ports" + int "Maximum number of 8250/16550 serial ports" depends on SERIAL_8250 default "4" help -- cgit v1.2.2