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authorDima Zavin <dima@android.com>2011-08-23 15:56:50 -0700
committerArve Hjønnevåg <arve@android.com>2013-07-01 13:34:58 -0700
commitf833f2c25f471bc999b64522d4f32de7eff4455b (patch)
tree046341b28a7b8641b2bf872bc095bf3712403382 /arch
parent59ace6e83677027aa4dd1fb0a436b6ddfe5e8a27 (diff)
ARM: add option to flush console before reboot
If the console_lock was held while the system was rebooted, the messages in the temporary logbuffer would not have propogated to all the console drivers. This force releases the console lock if it failed to be acquired. Change-Id: I193dcf7b968be17966833e50b8b8bc70d5d9fe89 Signed-off-by: Dima Zavin <dima@android.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/Kconfig9
-rw-r--r--arch/arm/kernel/process.c30
2 files changed, 39 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 136f263ed47..ecb2d6693f5 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1819,6 +1819,15 @@ config XEN
help
Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
+config ARM_FLUSH_CONSOLE_ON_RESTART
+ bool "Force flush the console on restart"
+ help
+ If the console is locked while the system is rebooted, the messages
+ in the temporary logbuffer would not have propogated to all the
+ console drivers. This option forces the console lock to be
+ released if it failed to be acquired, which will cause all the
+ pending messages to be flushed.
+
endmenu
menu "Boot options"
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index b18bd2f91d6..185f5b7e694 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -32,6 +32,7 @@
#include <linux/hw_breakpoint.h>
#include <linux/cpuidle.h>
#include <linux/leds.h>
+#include <linux/console.h>
#include <asm/cacheflush.h>
#include <asm/idmap.h>
@@ -60,6 +61,31 @@ static const char *isa_modes[] = {
extern void call_with_stack(void (*fn)(void *), void *arg, void *sp);
typedef void (*phys_reset_t)(unsigned long);
+#ifdef CONFIG_ARM_FLUSH_CONSOLE_ON_RESTART
+void arm_machine_flush_console(void)
+{
+ printk("\n");
+ pr_emerg("Restarting %s\n", linux_banner);
+ if (console_trylock()) {
+ console_unlock();
+ return;
+ }
+
+ mdelay(50);
+
+ local_irq_disable();
+ if (!console_trylock())
+ pr_emerg("arm_restart: Console was locked! Busting\n");
+ else
+ pr_emerg("arm_restart: Console was locked!\n");
+ console_unlock();
+}
+#else
+void arm_machine_flush_console(void)
+{
+}
+#endif
+
/*
* A temporary stack to use for CPU reset. This is static so that we
* don't clobber it with the identity mapping. When running with this
@@ -240,6 +266,10 @@ void machine_restart(char *cmd)
{
smp_send_stop();
+ /* Flush the console to make sure all the relevant messages make it
+ * out to the console drivers */
+ arm_machine_flush_console();
+
arm_pm_restart(reboot_mode, cmd);
/* Give a grace period for failure to restart of 1s */