On Fri, Aug 22, 2014 at 03:32:42AM +0200, Andreas F?rber wrote:

Hi,

Am 20.08.2014 02:45, schrieb Guenter Roeck:

quoted

The kernel core now supports a restart handler call chain for system
restart functions.

With this change, the arm_pm_restart callback is now optional, so
drop its initialization and check if it is set before calling it.
Only call the kernel restart handler if arm_pm_restart is not set.

[...]

quoted

diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 81ef686..ea279f7 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c

@@ -114,17 +114,13 @@ void soft_restart(unsigned long addr)
 	BUG();
 }
 
-static void null_restart(enum reboot_mode reboot_mode, const char *cmd)
-{
-}
-
 /*
  * Function pointers to optional machine specific functions
  */
 void (*pm_power_off)(void);
 EXPORT_SYMBOL(pm_power_off);
 
-void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd) = null_restart;
+void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd);

Stupid newbie question maybe, but isn't this variable uninitialized now,
like any non-static variable in C99? Or does the kernel assure that all
such "fields" are zero-initialized?

It is initialized with NULL, like all other global and static variables in the
kernel (and like pm_power_off a few lines above).

Guenter