Blackfin: allow NMI watchdog to be used w/RETN as a scratch reg

NMIs are not safe to return from because many anomaly workarounds are
implemented by disabling interrupts.  The NMI obviously violates this
assumption.  Since the NMI watchdog never returns, we don't have to
worry about it clobbering RETN when it is being used as a scratch register
with the exception stack.

Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

diff --git a/arch/blackfin/Kconfig.debug b/arch/blackfin/Kconfig.debug
index 3c49f76..d1825cb 100644 (file)
--- a/arch/blackfin/Kconfig.debug
+++ b/arch/blackfin/Kconfig.debug
@@ -238,7 +238,7 @@ config EARLY_PRINTK
 config NMI_WATCHDOG
        bool "Enable NMI watchdog to help debugging lockup on SMP"
        default n
-       depends on (SMP && !BFIN_SCRATCH_REG_RETN)
+       depends on SMP
        help
          If any CPU in the system does not execute the period local timer
          interrupt for more than 5 seconds, then the NMI handler dumps debug