From 0b7503bc0eef1b90c214059f2952539a2b89d8fe Mon Sep 17 00:00:00 2001 From: Dima Zavin Date: Tue, 23 Aug 2011 15:56:50 -0700 Subject: [PATCH] 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 --- arch/arm/Kconfig | 9 +++++++++ arch/arm/kernel/reboot.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 34e1569a11ee..88a56444749a 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1816,6 +1816,15 @@ 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/reboot.c b/arch/arm/kernel/reboot.c index 38269358fd25..1a06da8f0366 100644 --- 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 #include #include #include @@ -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 -- 2.34.1