diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2013-01-08 21:36:51 +0100 |
|---|---|---|
| committer | Anders Roxell <anders.roxell@linaro.org> | 2015-06-01 12:03:12 +0200 |
| commit | c38b35ff82083dc8c2ff48d67ecdc99f2e722054 (patch) | |
| tree | 4b61aac6d8c2e62d5b7beed846f5403b89e87725 /drivers | |
| parent | 999b05e05c791ecb6f813b2794171fe29c7051ef (diff) | |
drivers-tty-pl011-irq-disable-madness.patch
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/tty/serial/amba-pl011.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index b569011ac713..e6bbd3e6c898 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -1919,13 +1919,19 @@ pl011_console_write(struct console *co, const char *s, unsigned int count) clk_enable(uap->clk); - local_irq_save(flags); + /* + * local_irq_save(flags); + * + * This local_irq_save() is nonsense. If we come in via sysrq + * handling then interrupts are already disabled. Aside of + * that the port.sysrq check is racy on SMP regardless. + */ if (uap->port.sysrq) locked = 0; else if (oops_in_progress) - locked = spin_trylock(&uap->port.lock); + locked = spin_trylock_irqsave(&uap->port.lock, flags); else - spin_lock(&uap->port.lock); + spin_lock_irqsave(&uap->port.lock, flags); /* * First save the CR then disable the interrupts @@ -1947,8 +1953,7 @@ pl011_console_write(struct console *co, const char *s, unsigned int count) writew(old_cr, uap->port.membase + UART011_CR); if (locked) - spin_unlock(&uap->port.lock); - local_irq_restore(flags); + spin_unlock_irqrestore(&uap->port.lock, flags); clk_disable(uap->clk); } |