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ANDROID: ARM: add option to flush console before reboot

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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>
This commit is contained in:
Dima Zavin
2011-08-23 15:56:50 -07:00
committed by Dmitry Shmidt
parent f9deaf1b98
commit 2444662d5c
2 changed files with 39 additions and 0 deletions
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arch/arm/Kconfig
+9
View File
@@ -1836,6 +1836,15 @@ 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"
arch/arm/kernel/reboot.c
+30
View File
@@ -6,6 +6,7 @@
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/console.h>
#include <linux/cpu.h>
#include <linux/delay.h>
#include <linux/reboot.h>
@@ -122,6 +123,31 @@ void machine_power_off(void)
pm_power_off();
}
#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
/*
* Restart requires that the secondary CPUs stop performing any activity
* while the primary CPU resets the system. Systems with a single CPU can
@@ -138,6 +164,10 @@ void machine_restart(char *cmd)
local_irq_disable();
smp_send_stop();
/* Flush the console to make sure all the relevant messages make it
* out to the console drivers */
arm_machine_flush_console();
if (arm_pm_restart)
arm_pm_restart(reboot_mode, cmd);
else