diff options
Diffstat (limited to 'drivers/tty/serial/8250/8250_port.c')
-rw-r--r-- | drivers/tty/serial/8250/8250_port.c | 70 |
1 files changed, 52 insertions, 18 deletions
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 39e821d6e537..7ab066606b25 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -19,6 +19,7 @@ #include <linux/moduleparam.h> #include <linux/ioport.h> #include <linux/init.h> +#include <linux/irq.h> #include <linux/console.h> #include <linux/sysrq.h> #include <linux/delay.h> @@ -31,6 +32,7 @@ #include <linux/nmi.h> #include <linux/mutex.h> #include <linux/slab.h> +#include <linux/kdb.h> #include <linux/uaccess.h> #include <linux/pm_runtime.h> #include <linux/ktime.h> @@ -1522,6 +1524,8 @@ static inline void __stop_tx(struct uart_8250_port *p) if (em485) { unsigned char lsr = serial_in(p, UART_LSR); + p->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS; + /* * To provide required timeing and allow FIFO transfer, * __stop_tx_rs485() must be called only when both FIFO and @@ -1594,6 +1598,18 @@ static inline void start_tx_rs485(struct uart_port *port) if (!(up->port.rs485.flags & SER_RS485_RX_DURING_TX)) serial8250_stop_rx(&up->port); + /* + * While serial8250_em485_handle_stop_tx() is a noop if + * em485->active_timer != &em485->stop_tx_timer, it might happen that + * the timer is still armed and triggers only after the current bunch of + * chars is send and em485->active_timer == &em485->stop_tx_timer again. + * So cancel the timer. There is still a theoretical race condition if + * the timer is already running and only comes around to check for + * em485->active_timer when &em485->stop_tx_timer is armed again. + */ + if (em485->active_timer == &em485->stop_tx_timer) + hrtimer_try_to_cancel(&em485->stop_tx_timer); + em485->active_timer = NULL; mcr = serial8250_in_MCR(up); @@ -1851,10 +1867,13 @@ EXPORT_SYMBOL_GPL(serial8250_modem_status); static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir) { switch (iir & 0x3f) { - case UART_IIR_RX_TIMEOUT: - serial8250_rx_dma_flush(up); + case UART_IIR_RDI: + if (!up->dma->rx_running) + break; /* fall-through */ case UART_IIR_RLSI: + case UART_IIR_RX_TIMEOUT: + serial8250_rx_dma_flush(up); return true; } return up->dma->rx_dma(up); @@ -1868,6 +1887,7 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir) unsigned char status; unsigned long flags; struct uart_8250_port *up = up_to_u8250p(port); + struct tty_port *tport = &port->state->port; bool skip_rx = false; if (iir & UART_IIR_NO_INT) @@ -1891,6 +1911,11 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir) skip_rx = true; if (status & (UART_LSR_DR | UART_LSR_BI) && !skip_rx) { + struct irq_data *d; + + d = irq_get_irq_data(port->irq); + if (d && irqd_is_wakeup_set(d)) + pm_wakeup_event(tport->tty->dev, 0); if (!up->dma || handle_rx_dma(up, iir)) status = serial8250_rx_chars(up, status); } @@ -1946,19 +1971,25 @@ static int serial8250_tx_threshold_handle_irq(struct uart_port *port) static unsigned int serial8250_tx_empty(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); + unsigned int result = 0; unsigned long flags; unsigned int lsr; serial8250_rpm_get(up); spin_lock_irqsave(&port->lock, flags); - lsr = serial_port_in(port, UART_LSR); - up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS; + if (!serial8250_tx_dma_running(up)) { + lsr = serial_port_in(port, UART_LSR); + up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS; + + if ((lsr & BOTH_EMPTY) == BOTH_EMPTY) + result = TIOCSER_TEMT; + } spin_unlock_irqrestore(&port->lock, flags); serial8250_rpm_put(up); - return (lsr & BOTH_EMPTY) == BOTH_EMPTY ? TIOCSER_TEMT : 0; + return result; } unsigned int serial8250_do_get_mctrl(struct uart_port *port) @@ -2590,11 +2621,8 @@ static unsigned char serial8250_compute_lcr(struct uart_8250_port *up, if (c_cflag & CSTOPB) cval |= UART_LCR_STOP; - if (c_cflag & PARENB) { + if (c_cflag & PARENB) cval |= UART_LCR_PARITY; - if (up->bugs & UART_BUG_PARITY) - up->fifo_bug = true; - } if (!(c_cflag & PARODD)) cval |= UART_LCR_EPAR; #ifdef CMSPAR @@ -2708,8 +2736,7 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios, up->lcr = cval; /* Save computed LCR */ if (up->capabilities & UART_CAP_FIFO && port->fifosize > 1) { - /* NOTE: If fifo_bug is not set, a user can set RX_trigger. */ - if ((baud < 2400 && !up->dma) || up->fifo_bug) { + if (baud < 2400 && !up->dma) { up->fcr &= ~UART_FCR_TRIGGER_MASK; up->fcr |= UART_FCR_TRIGGER_1; } @@ -2903,8 +2930,10 @@ static int serial8250_request_std_resource(struct uart_8250_port *up) case UPIO_MEM32BE: case UPIO_MEM16: case UPIO_MEM: - if (!port->mapbase) + if (!port->mapbase) { + ret = -EINVAL; break; + } if (!request_mem_region(port->mapbase, size, "serial")) { ret = -EBUSY; @@ -3043,8 +3072,7 @@ static int do_set_rxtrig(struct tty_port *port, unsigned char bytes) struct uart_8250_port *up = up_to_u8250p(uport); int rxtrig; - if (!(up->capabilities & UART_CAP_FIFO) || uport->fifosize <= 1 || - up->fifo_bug) + if (!(up->capabilities & UART_CAP_FIFO) || uport->fifosize <= 1) return -EINVAL; rxtrig = bytes_to_fcr_rxtrig(up, bytes); @@ -3200,6 +3228,7 @@ void serial8250_init_port(struct uart_8250_port *up) struct uart_port *port = &up->port; spin_lock_init(&port->lock); + port->pm = NULL; port->ops = &serial8250_pops; up->cur_iotype = 0xFF; @@ -3253,15 +3282,20 @@ static void serial8250_console_restore(struct uart_8250_port *up) unsigned int baud, quot, frac = 0; termios.c_cflag = port->cons->cflag; - if (port->state->port.tty && termios.c_cflag == 0) + termios.c_ispeed = port->cons->ispeed; + termios.c_ospeed = port->cons->ospeed; + if (port->state->port.tty && termios.c_cflag == 0) { termios.c_cflag = port->state->port.tty->termios.c_cflag; + termios.c_ispeed = port->state->port.tty->termios.c_ispeed; + termios.c_ospeed = port->state->port.tty->termios.c_ospeed; + } baud = serial8250_get_baud_rate(port, &termios, NULL); quot = serial8250_get_divisor(port, baud, &frac); serial8250_set_divisor(port, baud, quot, frac); serial_port_out(port, UART_LCR, up->lcr); - serial8250_out_MCR(up, UART_MCR_DTR | UART_MCR_RTS); + serial8250_out_MCR(up, up->mcr | UART_MCR_DTR | UART_MCR_RTS); } /* @@ -3282,9 +3316,9 @@ void serial8250_console_write(struct uart_8250_port *up, const char *s, serial8250_rpm_get(up); - if (port->sysrq) + if (port->sysrq || oops_in_progress) locked = 0; - else if (oops_in_progress) + else if (in_kdb_printk()) locked = spin_trylock_irqsave(&port->lock, flags); else spin_lock_irqsave(&port->lock, flags); |