ARM: add option to flush console before reboot

[firefly-linux-kernel-4.4.55.git] / arch / arm / kernel / reboot.c

diff --git a/arch/arm/kernel/reboot.c b/arch/arm/kernel/reboot.c
index 38269358fd252c6bb93fd58a0478319c436cdfd3..1a06da8f0366d9b1056f220c26d9386219f09c60 100644 (file)
--- a/arch/arm/kernel/reboot.c
+++ b/arch/arm/kernel/reboot.c
@@ -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>
@@ -124,6 +125,31 @@ 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
@@ -140,6 +166,10 @@ 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