diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2013-01-08 21:36:51 +0100 |
|---|---|---|
| committer | Anders Roxell <anders.roxell@linaro.org> | 2015-05-08 22:32:23 +0200 |
| commit | 9e915a1fa4d56e4d226a4a66c1285f3eb4d264d9 (patch) | |
| tree | a2b985b58f8765d27906c7838c06a45f62876505 /drivers/tty | |
| parent | cb7b35509431aac5b7486e3686762f2a4b51f63e (diff) | |
drivers-tty-pl011-irq-disable-madness.patch
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Diffstat (limited to 'drivers/tty')
| -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 02016fcd91b8..5ef2c62bb904 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -1935,13 +1935,19 @@ 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 @@ -1963,8 +1969,7 @@ 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); } |