diff options
| author | Jason Wessel <jason.wessel@windriver.com> | 2011-07-28 12:42:23 -0500 |
|---|---|---|
| committer | Clark Williams <williams@redhat.com> | 2012-03-07 16:15:15 -0600 |
| commit | 79fd0d6814967cf8c2b50a688ca76ed47920586b (patch) | |
| tree | a43a6fd31e84882a1f647e26c538abafbf82cfc9 /drivers | |
| parent | f33b89c6fb3e500e9ee19ea6e4183ef637a05492 (diff) | |
kgdb/serial: Short term workaround
On 07/27/2011 04:37 PM, Thomas Gleixner wrote:
> - KGDB (not yet disabled) is reportedly unusable on -rt right now due
> to missing hacks in the console locking which I dropped on purpose.
>
To work around this in the short term you can use this patch, in
addition to the clocksource watchdog patch that Thomas brewed up.
Comments are welcome of course. Ultimately the right solution is to
change separation between the console and the HW to have a polled mode
+ work queue so as not to introduce any kind of latency.
Thanks,
Jason.
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/tty/serial/8250.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/drivers/tty/serial/8250.c b/drivers/tty/serial/8250.c index 3bf482cb7f51..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> @@ -2855,10 +2856,14 @@ serial8250_console_write(struct console *co, const char *s, unsigned int count) touch_nmi_watchdog(); - if (up->port.sysrq || oops_in_progress) - locked = spin_trylock_irqsave(&up->port.lock, flags); - else - spin_lock_irqsave(&up->port.lock, flags); + if (unlikely(in_kdb_printk())) { + locked = 0; + } 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 |