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authorDima Zavin <dima@android.com>2011-08-23 15:56:50 -0700
committerDima Zavin <dima@android.com>2011-08-23 16:10:22 -0700
commit76594495616ae4080423f77cbbe1572d954edb29 (patch)
treeaf850819c338d6d5fd3dd34a60c101702b38053f
parentcd1313b42474ea742981fc2f7d1a1a30f3e53e29 (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>
-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 9adc278a22a..81f0b93a0cb 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1671,6 +1671,15 @@ config DEPRECATED_PARAM_STRUCT
This was deprecated in 2001 and announced to live on for 5 years.
Some old boot loaders still use this way.
+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 919de7c84f7..34fca2e272c 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -30,6 +30,7 @@
#include <linux/uaccess.h>
#include <linux/random.h>
#include <linux/hw_breakpoint.h>
+#include <linux/console.h>
#include <asm/cacheflush.h>
#include <asm/processor.h>
@@ -90,8 +91,37 @@ static int __init hlt_setup(char *__unused)
__setup("nohlt", nohlt_setup);
__setup("hlt", hlt_setup);
+#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
+
void arm_machine_restart(char mode, const char *cmd)
{
+ /* Flush the console to make sure all the relevant messages make it
+ * out to the console drivers */
+ arm_machine_flush_console();
+
/* Disable interrupts first */
local_irq_disable();
local_fiq_disable();