[PATCH] debug: add sysrq_always_enabled boot option

Most distributions enable sysrq support but set it to 0 by default.  Add a
sysrq_always_enabled boot option to always-enable sysrq keys.  Useful for
debugging - without having to modify the disribution's config files (which
might not be possible if the kernel is on a live CD, etc.).

Also, while at it, clean up the sysrq interfaces.

[bunk@stusta.de: make sysrq_always_enabled_setup() static]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 4 insertions, 6 deletions

diff --git a/drivers/char/viocons.c b/drivers/char/viocons.c
index 6d2e314860df..0e0da443cbd5 100644
--- a/drivers/char/viocons.c
+++ b/drivers/char/viocons.c
@@ -61,10 +61,7 @@
 static DEFINE_SPINLOCK(consolelock);
 static DEFINE_SPINLOCK(consoleloglock);
 
-#ifdef CONFIG_MAGIC_SYSRQ
 static int vio_sysrq_pressed;
-extern int sysrq_enabled;
-#endif
 
 #define VIOCHAR_NUM_BUF         16
 
@@ -936,8 +933,10 @@ static void vioHandleData(struct HvLpEvent *event)
          */
         num_pushed = 0;
         for (index = 0; index < cevent->len; index++) {
-#ifdef CONFIG_MAGIC_SYSRQ
-                if (sysrq_enabled) {
+                /*
+                 * Will be optimized away if !CONFIG_MAGIC_SYSRQ:
+                 */
+                if (sysrq_on()) {
                         /* 0x0f is the ascii character for ^O */
                         if (cevent->data[index] == '\x0f') {
                                 vio_sysrq_pressed = 1;
@@ -956,7 +955,6 @@ static void vioHandleData(struct HvLpEvent *event)
                                 continue;
                         }
                 }
-#endif
                 /*
                  * The sysrq sequence isn't included in this check if
                  * sysrq is enabled and compiled into the kernel because