Subject: tty/serial/omap: Make the locking RT aware From: Thomas Gleixner Date: Thu, 28 Jul 2011 13:32:57 +0200 Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.18/older/patches-4.18.5-rt3.tar.xz 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/omap-serial.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -1307,13 +1307,10 @@ serial_omap_console_write(struct console pm_runtime_get_sync(up->dev); - local_irq_save(flags); - if (up->port.sysrq) - locked = 0; - else if (oops_in_progress) - locked = spin_trylock(&up->port.lock); + if (up->port.sysrq || oops_in_progress) + locked = spin_trylock_irqsave(&up->port.lock, flags); else - spin_lock(&up->port.lock); + spin_lock_irqsave(&up->port.lock, flags); /* * First save the IER then disable the interrupts @@ -1342,8 +1339,7 @@ serial_omap_console_write(struct console pm_runtime_mark_last_busy(up->dev); pm_runtime_put_autosuspend(up->dev); if (locked) - spin_unlock(&up->port.lock); - local_irq_restore(flags); + spin_unlock_irqrestore(&up->port.lock, flags); } static int __init