diff options
Diffstat (limited to 'drivers/tty/serial/8250.c')
| -rw-r--r-- | drivers/tty/serial/8250.c | 29 |
1 files changed, 19 insertions, 10 deletions
diff --git a/drivers/tty/serial/8250.c b/drivers/tty/serial/8250.c index eeadf1b8e093..0596a359d30c 100644 --- a/drivers/tty/serial/8250.c +++ b/drivers/tty/serial/8250.c @@ -38,6 +38,7 @@ #include <linux/nmi.h> #include <linux/mutex.h> #include <linux/slab.h> +#include <linux/kdb.h> #include <asm/io.h> #include <asm/irq.h> @@ -81,7 +82,16 @@ static unsigned int skip_txen_test; /* force skip of txen test at init time */ #define DEBUG_INTR(fmt...) do { } while (0) #endif -#define PASS_LIMIT 512 +/* + * On -rt we can have a more delays, and legitimately + * so - so don't drop work spuriously and spam the + * syslog: + */ +#ifdef CONFIG_PREEMPT_RT_FULL +# define PASS_LIMIT 1000000 +#else +# define PASS_LIMIT 512 +#endif #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE) @@ -2846,14 +2856,14 @@ serial8250_console_write(struct console *co, const char *s, unsigned int count) touch_nmi_watchdog(); - local_irq_save(flags); - if (up->port.sysrq) { - /* serial8250_handle_port() already took the lock */ + if (unlikely(in_kdb_printk())) { locked = 0; - } else if (oops_in_progress) { - locked = spin_trylock(&up->port.lock); - } else - spin_lock(&up->port.lock); + } else { + if (up->port.sysrq || oops_in_progress) + locked = spin_trylock_irqsave(&up->port.lock, flags); + else + spin_lock_irqsave(&up->port.lock, flags); + } /* * First save the IER then disable the interrupts @@ -2885,8 +2895,7 @@ serial8250_console_write(struct console *co, const char *s, unsigned int count) check_modem_status(up); if (locked) - spin_unlock(&up->port.lock); - local_irq_restore(flags); + spin_unlock_irqrestore(&up->port.lock, flags); } static int __init serial8250_console_setup(struct console *co, char *options) |