diff options
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/n_hdlc.c | 5 | ||||
| -rw-r--r-- | drivers/tty/serial/owl-uart.c | 2 | ||||
| -rw-r--r-- | drivers/tty/serial/sc16is7xx.c | 28 | ||||
| -rw-r--r-- | drivers/tty/serial/serial_mctrl_gpio.c | 3 |
4 files changed, 37 insertions, 1 deletions
diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c index 08bd6b965847..e83dea8d6633 100644 --- a/drivers/tty/n_hdlc.c +++ b/drivers/tty/n_hdlc.c @@ -969,6 +969,11 @@ static int __init n_hdlc_init(void) } /* end of init_module() */ +#ifdef CONFIG_SPARC +#undef __exitdata +#define __exitdata +#endif + static const char hdlc_unregister_ok[] __exitdata = KERN_INFO "N_HDLC: line discipline unregistered\n"; static const char hdlc_unregister_fail[] __exitdata = diff --git a/drivers/tty/serial/owl-uart.c b/drivers/tty/serial/owl-uart.c index b9c859365334..d774f6013d7b 100644 --- a/drivers/tty/serial/owl-uart.c +++ b/drivers/tty/serial/owl-uart.c @@ -754,7 +754,7 @@ static int __init owl_uart_init(void) return ret; } -static void __init owl_uart_exit(void) +static void __exit owl_uart_exit(void) { platform_driver_unregister(&owl_uart_platform_driver); uart_unregister_driver(&owl_uart_driver); diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index e48523da47ac..c1655aba131f 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -333,6 +333,7 @@ struct sc16is7xx_port { struct kthread_worker kworker; struct task_struct *kworker_task; struct kthread_work irq_work; + struct mutex efr_lock; struct sc16is7xx_one p[0]; }; @@ -504,6 +505,21 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud) div /= 4; } + /* In an amazing feat of design, the Enhanced Features Register shares + * the address of the Interrupt Identification Register, and is + * switched in by writing a magic value (0xbf) to the Line Control + * Register. Any interrupt firing during this time will see the EFR + * where it expects the IIR to be, leading to "Unexpected interrupt" + * messages. + * + * Prevent this possibility by claiming a mutex while accessing the + * EFR, and claiming the same mutex from within the interrupt handler. + * This is similar to disabling the interrupt, but that doesn't work + * because the bulk of the interrupt processing is run as a workqueue + * job in thread context. + */ + mutex_lock(&s->efr_lock); + lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG); /* Open the LCR divisors for configuration */ @@ -519,6 +535,8 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud) /* Put LCR back to the normal mode */ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr); + mutex_unlock(&s->efr_lock); + sc16is7xx_port_update(port, SC16IS7XX_MCR_REG, SC16IS7XX_MCR_CLKSEL_BIT, prescaler); @@ -701,6 +719,8 @@ static void sc16is7xx_ist(struct kthread_work *ws) { struct sc16is7xx_port *s = to_sc16is7xx_port(ws, irq_work); + mutex_lock(&s->efr_lock); + while (1) { bool keep_polling = false; int i; @@ -710,6 +730,8 @@ static void sc16is7xx_ist(struct kthread_work *ws) if (!keep_polling) break; } + + mutex_unlock(&s->efr_lock); } static irqreturn_t sc16is7xx_irq(int irq, void *dev_id) @@ -904,6 +926,9 @@ static void sc16is7xx_set_termios(struct uart_port *port, if (!(termios->c_cflag & CREAD)) port->ignore_status_mask |= SC16IS7XX_LSR_BRK_ERROR_MASK; + /* As above, claim the mutex while accessing the EFR. */ + mutex_lock(&s->efr_lock); + sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_CONF_MODE_B); @@ -925,6 +950,8 @@ static void sc16is7xx_set_termios(struct uart_port *port, /* Update LCR register */ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr); + mutex_unlock(&s->efr_lock); + /* Get baud rate generator configuration */ baud = uart_get_baud_rate(port, termios, old, port->uartclk / 16 / 4 / 0xffff, @@ -1187,6 +1214,7 @@ static int sc16is7xx_probe(struct device *dev, s->regmap = regmap; s->devtype = devtype; dev_set_drvdata(dev, s); + mutex_init(&s->efr_lock); kthread_init_worker(&s->kworker); kthread_init_work(&s->irq_work, sc16is7xx_ist); diff --git a/drivers/tty/serial/serial_mctrl_gpio.c b/drivers/tty/serial/serial_mctrl_gpio.c index 42e42e3e7a6e..388f71046849 100644 --- a/drivers/tty/serial/serial_mctrl_gpio.c +++ b/drivers/tty/serial/serial_mctrl_gpio.c @@ -69,6 +69,9 @@ EXPORT_SYMBOL_GPL(mctrl_gpio_set); struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios, enum mctrl_gpio_idx gidx) { + if (gpios == NULL) + return NULL; + return gpios->gpio[gidx]; } EXPORT_SYMBOL_GPL(mctrl_gpio_to_gpiod); |