Subject: tty/serial/pl011: Make the locking work on RT From: Thomas Gleixner Date: Tue Jan 8 21:36:51 2013 +0100 Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz From: Thomas Gleixner The lock is a sleeping lock and local_irq_save() is not the optimsation we are looking for. Redo it to make it work on -RT and non-RT. Signed-off-by: Thomas Gleixner --- drivers/tty/serial/amba-pl011.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) --- --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -2332,13 +2332,10 @@ pl011_console_write(struct console *co, clk_enable(uap->clk); - local_irq_save(flags); - if (uap->port.sysrq) - locked = 0; - else if (oops_in_progress) - locked = uart_port_trylock(&uap->port); + if (uap->port.sysrq || oops_in_progress) + locked = uart_port_trylock_irqsave(&uap->port, &flags); else - uart_port_lock(&uap->port); + uart_port_lock_irqsave(&uap->port, &flags); /* * First save the CR then disable the interrupts @@ -2364,8 +2361,7 @@ pl011_console_write(struct console *co, pl011_write(old_cr, uap, REG_CR); if (locked) - uart_port_unlock(&uap->port); - local_irq_restore(flags); + uart_port_unlock_irqrestore(&uap->port, flags); clk_disable(uap->clk); }